Abstracts: 48th Annual Conference of the American College of Veterinary Ophthalmologists, Baltimore, MD October 11‐14, 2017

Paper Abstracts

Surgical repair of pseudopterygium‐like symblepharon in a cat

RA Allbaugh, TS Strong and RA Strauss

Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, USA

Purpose: To describe successful surgical treatment of symblepharon in a cat that presented with pseudopterygium‐like conjunctival and third eyelid incorporation without corneal adhesions. Methods: A 1‐year‐old spayed female domestic shorthair cat presented with symblepharon affecting conjunctival and third eyelid tissues that resulted in a nonadherent circumferential veil of annular conjunctival tissue over healthy, unaffected cornea. The appearance morphologically resembled pseudopterygium. Surgical repair utilizing a technique described in rabbits for the treatment of aberrant conjunctival stricture and overgrowth (pseudopterygium) was performed dorsally and ventrolaterally to reflect the conjunctiva back into the fornix, while the third eyelid was partially transected to clear the ventromedial visual axis. Results: Surgical inversion of the conjunctival tissues and transpalpebral fixation reformed the fornices and effectively cleared corneal obstruction dorsally and ventrolaterally. The third eyelid required partial resection to clear corneal obstruction ventromedially. Postoperatively, the patient healed well from surgery and has had no recurrence of symblepharon or adverse effects from partial third eyelid excision in the subsequent months. Conclusions: This surgical technique, originally reported to benefit rabbits with pseudopterygium, offered utility in a cat afflicted with pseudopterygium‐like symblepharon and could be considered in similar cases to improve vision and cosmesis. None

Comparison of bacterial culture results collected via direct corneal wound sampling versus conjunctival fornix in canine eyes with presumed infectious ulcerative keratitis

CR Auten,¹ JL Urbanz¹ and DD Dees²

¹Eye Care for Animals, North Scottsdale, AZ, USA; ²Eye Care for Animals, Austin, TX, USA

Purpose: To compare aerobic bacterial culture results in eyes with presumed infected corneal ulcers between direct wound sampling and samples obtained from the lower conjunctival fornix. Methods: Microbial swabs were collected by direct sampling of the infected corneal ulcer as well as the lower conjunctival fornix. Results: One hundred twelve samples were obtained from 56 eyes of 55 dogs. Sixty‐eight samples (61%) yielded bacterial growth. No bacterial growth was obtained from either sampling site in 19 eyes. Positive growth from both sites was obtained in 31 eyes. Six eyes yielded bacterial growth from the fornix but not from the cornea. Overall, 31/56 eyes (55%) were positive at the cornea and 37/56 eyes (66%) were positive at the fornix. Twenty different bacterial isolates were obtained from 68 positive samples. Gram positive (71%) organisms were more common than Gram negative (29%). The most commonly isolated organisms were Staphylococcus pseudintermedius (25%), Beta hemolytic Streptococcus spp. (23%), and Pseudomonas aeruginosa (12%). Methicillin‐resistant organisms were isolated in 9% of samples. Comparison of organisms isolated from the two collection sites of the same eye revealed an exact correlation in 43/56 eyes (77%) and differed in 13/56 eyes (23%). Conclusion: Sampling from the conjunctival fornix may be a suitable alternative to direct wound sampling in eyes with compromised corneal structural integrity. None.

Yucatan minipig choroidal neovascularization: a laser‐induced model of human neovascular age‐related macular degeneration

JT Bartoe,¹ RF Boyd,¹ K Yekkala,² BM Geddings,¹ MT Leahy,¹ A Quiambao,³ DJ Nuno,³ Rafal Farjo³ and TS Vihtelic¹

¹Ophthalmology Services, MPI Research; ²Anatomic Pathology, MPI Research; ³EyeCRO

Purpose: Historically, large animal models of neovascular age‐related macular degeneration (AMD) have been unpredictable. Only 70% of laser‐induced choroidal neovascularization (CNV) lesions in non‐human primates (NHP) are considered clinically relevant and only up to 40% of lesions ideal, exhibiting Grade IV leakage on fluorescein angiography (FA). This inefficiency leads to excess animal use and high study cost. Previous swine CNV models reported extensive retinal damage and minimal choroidal involvement when neovascularization was present. Our study aimed to create a reproducible, predictable swine model of laser‐induced CNV; improving efficiency and lowering cost compared to available NHP CNV models. Methods: 15 Yucatan minipigs were used. Bilaterally, six lesions were created along the visual streak using a slit‐lamp targeted, 532 nm argon laser. Follow‐up examinations included optical coherence tomography (OCT), FA and ocular histopathology. Results: Optimized laser settings reliably ruptured Bruch's membrane as demonstrated on OCT. These membrane disruptions showed ingrowth of hyperreflective tissue into the outer retinal layers and hyperfluorescence on FA, suggesting fibrovascular proliferation from choroid into retina. Histopathological characterization supported in vivo findings with moderate to marked subretinal fibrosis and neovascularization extending from the choroid into outer nuclear layer. Inner retina remained generally unaffected. Conclusions: Yucatan minipig is an excellent alternative to other large models of neovascular AMD. Similar globe size and retinal anatomy to human patients makes the model ideal for generating efficacy, pharmacokinetic, and safety data; all in the same species for investigational molecules targeting proliferative posterior segment disease.

Factors affecting publication in peer‐reviewed journals of abstracts presented from 2008–2012 ACVO meetings

E Bentley,¹ M Koester,¹ T Bdolah‐Abram,² N Yair² and R Ofri²

¹School of Veterinary Medicine, University of Wisconsin‐Madison, Madison, WI, USA; ²Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Jerusalem, Israel

Purpose: The aim of this study was to examine variables that affect publication of ACVO meeting abstracts in peer‐reviewed journals and compare results to the ECVO publication rate (PR). Methods: Published papers were identified via online searches for abstracts from 2008–2012 ACVO/ECVO meetings. Variables analyzed (via Pearson Chi‐Square test) included: oral presentation/poster, type of abstract (clinical/basic science/case report), species, ocular tissue studied, nationality, funding, first/last/any author a diplomate, resident as first author, and author affiliation (private practice/university). Results: 186/577 ACVO abstracts were published within 608 ± 479 days, with 103 published in Veterinary Ophthalmology. Significant factors included: nationality of first/last authors (P = 0.005); English as first language (P < 0.001); type of presentation (P < 0.001, oral 40% PR, poster 22% PR); type of study (P = 0.037, clinical study 35% PR, basic science 30% PR, case report 16% PR); resident as first author (P < 0.001); diplomate as any author except first/last (P < 0.001); first author affiliation (P = 0.001, university 37% PR, practice 21% PR); last author affiliation (P = 0.003, university 36% PR, practice 22% PR); and species studied (P < 0.001, horses 53% PR, multiple species 50% PR, cats 35% PR, food animals 31% PR, exotics/wildlife 31% PR, dogs 27% PR, lab animals/in vitro 24%). Non‐significant factors were: diplomate as first/last author, funding, and ocular tissue studied. Type of presentation, resident as first author, university affiliation of first author, and species had the greatest effect on publication probability. ECVO PR was 87/299, which was not significantly different from ACVO PR (P = 0.191). Conclusion: At 32%, ACVO PR is similar to ECVO PR of 29%.

Fluorescein versus indocyanine green angiography to evaluate glaucomatous damage of the ocular fundus in beagles with ADAMTS10 open angle glaucoma (ADAMTS10‐OAG)

J Burn,¹ CD Harman,¹ KL Koehl,¹ FD Nussdorfer,¹ ES Storey,² KN Gelatt,³ CE Plummer³ and AM Komáromy^1,3,4

¹Michigan State University; ²South Atlanta Veterinary Emergency and Specialty; ³University of Florida; ⁴University of Pennsylvania

Purpose: To evaluate retinal, choroidal, and optic nerve head (ONH) vascular perfusion in beagles with ADAMTS10‐OAG using fluorescein (FA) and indocyanine green angiography (ICGA). Methods: Fluorescein (20 mg/kg) and/or ICG (1 mg/kg) was injected intravenously and angiograms were recorded with the Spectralis^® Confocal Scanning Ophthalmoscope (Heidelberg Engineering). Three groups of beagles were examined: (1) pre‐glaucomatous mutant (mean diurnal intraocular pressure [IOP] <20 mmHg; 0.5–4.5 years; n = 15); (2) glaucomatous mutant (IOP > 20 mmHg; 1.5–10.8 years; n = 23); and (3) non‐mutant controls (0.5–6.6 years; n = 5). Routine ophthalmic examinations and fundus imaging by spectral domain optical coherence tomography (SD‐OCT; Spectralis^®) were performed. Results: Group 1: 3/15 dogs showed wedge‐shaped areas of delayed choroidal filling and 1/15 also showed delayed superior retinal venule filling. Group 2: 10/23 dogs had a combination of wedge‐shaped areas of delayed choroidal filling, delayed superior retinal venule filling, peripapillary and ONH hyperfluorescence. Only 1/5 control dogs showed wedge‐shaped areas of delayed choroidal filling. The abnormalities were more distinct with FA than ICGA. OCT imaging showed wedge‐shaped retinal thinning in the area of delayed perfusion in 2/23 dogs in Group 2. Hyperfluorescence in and around the ONH was associated with severe thinning of the nerve fiber layer in advanced disease. Conclusions: Wedge‐shaped retinal defects are seen in dogs with advanced glaucoma. Our study showed that delayed vascular perfusion in choroidal watershed zones are likely responsible for these defects. Supported by Michigan State University startup funds and Edward Sheppard and family. None.

A survey of orbital disease associated with exophthalmos in ferrets (Mustela putorius furo)

ZN Cochrane,¹ RA Allbaugh,¹ TD Strong¹ and LB Teixeira²

¹Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, USA; ²Comparative Ocular Pathology Lab of Wisconsin (COPLOW), University of Wisconsin‐Madison School of Veterinary Medicine, Madison, WI, USA

Purpose: To survey and organize the known causes of orbital disease manifesting as exophthalmia in ferrets (Mustela putorius furo).Methods: An extensive literature review was conducted along with a thorough analysis of the COPLOW database in search of ferret orbital disease following management of a case at the Iowa State University Lloyd Veterinary Medical Center (ISU LVMC). A qualifier for inclusion into this study was that the patient's exophthalmos had to be observed by the clinician at the time of presentation. Results: Out of the 17 recorded ferret cases in the COPLOW database, 7 (41.1%) represented orbital disease. A literature review revealed 8 additional documented case reports of retrobulbar disease in ferrets. Including the single case seen at the ISU LVMC that prompted this survey, in total 16 cases of ferret orbital disease were identified. Of these 16 cases, 4 (25%) were caused by a zygomatic salivary mucocele, 7 (43.8%) were confirmed as orbital lymphoma, and 5 (31.2%) were diagnosed as orbital adenocarcinoma. The average age of diagnosis for the ferrets with zygomatic salivary mucoceles was 4.3 years. The average age of enucleation was 6.5 years for the lymphoma cases and 4.3 years for the adenocarcinoma cases. Conclusions: The purpose of this survey is to provide veterinarians with an updated resource of information regarding causes of exophthalmos in pet ferrets. This is the first reported study that specifically reviews the known contributors to orbital disease and can aid in creating prioritized differential diagnoses in ferrets presenting with exophthalmos. No outside funding was provided in support of this research. None.

Keratomycosis in 14 dogs and 1 cat in South Florida

CMH Colitz and V Ternullo

All Animal Eye Care, Inc.

Purpose: To describe 15 cases of keratomycosis in 14 dogs and 1 cat in Jupiter, Florida. Methods: Ophthalmologic evaluation including cytology was performed on each patient. All had fungal elements on cytology; cultures were submitted in 2 cases. Results: There were 14 dogs (5–14yo, X = 8.8y; 3 Boston terriers, 2 Chihuahuas, and one of a variety of other breeds) and 1 cat (13yo Turkish Van). Two dogs were diabetic and 11 dogs had keratoconjunctivitis sicca. One dog and cat were taking oral prednisone, 2 dogs had recent phacoemulsification and were on topical 1% prednisolone acetate. The 2 diabetic dogs had stromal abscesses and the non‐diabetic dogs had corneal ulcers, the cat had bullous keratopathy. Three dogs and the cat were treated with oral fluconazole, 3 resolved, 1 did not and developed a melting corneal ulcer requiring surgery. Three dogs were treated with topical 1% voriconazole ointment and oral fluconazole; 2 resolved, 1 did not, treatment was changed to oral terbinafine and resolved. Four patients were treated with 1% voriconazole ointment, 1 healed, 1 required keratectomy with conjunctival pedical flap, 2 resolved with addition of oral terbinafine. Two dogs were treated with oral terbinafine, both resolved; and 3 dogs were treated with topical 1% voriconazole and terbinafine and resolved. Conclusions: Patients treated with oral terbinafine or a combination of terbinafine and topical voriconazole healed without need for surgery or change in therapy. Treatment with topical voriconazole alone was least successful, and oral fluconazole with or without topical voriconazole was variably successful. None.

Prophylactic and therapeutic effects of two famciclovir doses on infectious upper respiratory disease in shelter‐housed cats

AE Cooper,¹ SM Thomasy,¹ TL Drazenovich,¹ PH Kass,¹ SS Potnis,¹ CM Leutenegger² and DJ Maggs¹

¹School of Veterinary Medicine, University of California Davis, Davis, CA, USA; ²IDEXX Laboratories, Sacramento, CA, USA

Purpose: In humans with herpetic disease, early or pre‐emptive famciclovir therapy reduces disease duration and severity. This prospective, masked, placebo‐controlled study tested therapeutic and prophylactic effects of famciclovir (Apotex, Ontario, Canada) given at one of 2 doses to cats beginning at shelter entry. Methods: Cats were assigned to therapeutic or prophylactic arms of the study based on presence or absence of clinical signs of herpetic disease, respectively. Cats in each arm received no treatment or famciclovir at ˜30 or ˜90 mg/kg PO BID for 7 days. In the therapeutic arm a 4^th group was placebo‐treated. Disease scores, body weight, conjunctival feline herpesvirus (FHV‐1) shedding, and adoption rates were recorded at Days 1, 8, and 15. Data were analyzed using exact logistic regression (significance at P < 0.05) and Kaplan‐Meier survival curves. Results: No significant differences in clinical scores were observed among groups in the prophylactic or therapeutic arms at any of the 3 time‐points. Within the therapeutic arm, viral shedding was significantly higher at Day 8 in cats receiving no treatment compared to those receiving ˜90 mg/kg famciclovir but this effect failed to persist after famciclovir cessation (Day 15). No significant differences in adoption rates were detected among groups in either arm throughout the study. Conclusions: Famciclovir administered at ˜30 or ˜90 mg/kg BID for one week does not effectively prevent or treat clinical signs of herpetic disease in shelter‐housed cats but may reduce viral shedding when administered at ˜90 mg/kg BID. Supported by Morris Animal Foundation grant D16FE‐018 and UC Davis Cello Ophthalmology Endowment. None.

Effects of transscleral micropulse cyclophotocoagulation on corneal sensitivity in the eyes of 5 dogs treated for glaucoma

EE Crabtree, JS Sapienza and EN Rodriguez

Long Island Veterinary Specialists, Plainview, NY, USA

Purpose: To determine if transscleral cyclophotocoagulation with a micropulse diode laser decreases corneal sensitivity. Methods: Dogs with glaucoma that were treated at Long Island Veterinary Specialists with a novel transscleral diode 810 nm wavelength micropulse laser (Iridex Instruments) were selected for this study. A Luneau Cochet‐Bonnet aesthesiometer was used to measure the corneal touch threshold (CTT) in the central region of each patient's affected eye before surgery, 24‐h after surgery and within 2‐weeks post surgery. One person performed all CTT values. Results: There were 5 laser‐treated eyes included in this study: 2 OS and 3 OD. The parameters for the micropulse laser settings ranged from 140SX2400 mW–2800 mW. The mean CTT prior to cyclophotocoagulation was 1.6 gm/mm² (range: 1–2.8 gm/mm²), which was lower than the mean CTT 24‐h post surgery 5.7 gm/mm² (range: 1.8 > 15.9 gm/mm²). By 6–8 days post surgery, the mean CTT of all 5 dogs decreased to 2 gm/mm² (range: 0.8–2.8 gm/mm²). The CTT of dogs (n = 2) followed 2–4 weeks post surgery ranged 1–1.8 gm/mm². Two of the dogs developed indolent corneal ulcers that resolved within 2–3 weeks. Conclusions: A decrease in corneal sensitivity was demonstrated 1‐day post‐micropulse cyclophotocoagulation in all dogs. Corneal sensitivity increased 6–8 days in all dogs, suggesting that the micropulse laser's effects on the corneal nerves were transient. Two dogs in this study developed indolent corneal ulcers post‐laser therapy that ultimately healed. Due to low number of eyes in this study, additional investigation to further elucidate these findings and to determine correlation of corneal sensitivity to post surgical complications are warranted. None.

Risk factors associated with postoperative orbital infections in 182 horses undergoing enucleation

EE Crabtree,¹ RB Edwards III,¹ EL Kilgallon,² A Dwyer³ and M Lassaline⁴

¹Fairfield Equine Associates, Davis, CA, USA; ²Miller and Associates, Davis, CA, USA; ³Genesee Valley Equine Clinic, Davis, CA, USA; ⁴Department of Surgical & Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA

Purpose: To determine the association between horse's age, pituitary pars intermedia dysfunction (PPID), postoperative systemic antibiotic use, anesthetic protocol (general anesthesia vs. standing sedation), surgical location (stable vs. hospital), and duration of hospitalization on the development of postoperative orbital infections. Method: Retrospective review of medical records from horses undergoing enucleation at Fairfield Equine Associates, Miller and Associates, University of California‐Davis, and Genesee Valley Equine clinic from 2000–2017. Fisher's exact test was used to evaluate the association between age, PPID, antibiotic use, anesthetic protocol, surgical location and hospitalization duration and orbital infection (P‐value < 0.05). Results: A total of 182 horses met inclusion criteria, including 63 mares, 112 geldings and 7 stallions with a median age of 18 years (range 1–36 years). Surgeries were performed under general anesthesia (n = 56 inhalation; n = 7 IV general anesthesia) or standing sedation (n = 7 stable setting; n = 119 hospitalized setting). The length of stay for hospitalized horses was a mean of 3 days (range 0–25 days). Orbital infections occurred in 8/182 enucleations (4%). Increased risk of orbital infection was associated with PPID (P = 0.009), but not age, specific antibiotic use or duration, duration of hospitalization, anesthetic protocol, or surgical location. Conclusions: Horses with PPID may be at increased risk for orbital infection following enucleation. Therefore, antimicrobial therapy, diligent asepsis including intraoperative wound lavage, and postoperative wound care may be more important in these patients. Assessment and management of their endocrine status should be considered in the management of older horses undergoing enucleation. None.

Bandage contact lens retention time in dogs

KA Diehl, AC Bowden, DA Knudsen and KE Myrna

Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA

Purpose: To assess and compare retention time, ease of application, and patient tolerance of various bandage contact lens types from four different manufacturers. Methods: Five bandage contact lens types from 2 veterinary contact lens brands (An‐Vision D1 and D4; and Keragenix HRT 78, AL I‐B HRT‐78, and HydroBlues) and 4 lens types from 2 human contact lens brands (Bausch & Lomb PureVision and PureVision 2; and Acuvue Oasys without and with Hydroclear Plus) were evaluated in 6 Beagles. Ease of placement, the dogs’ tolerance of the lenses and their retention time for up to 14 days were recorded. Statistical analysis with a linear mixed model was performed. Results: The veterinary‐specific lenses had an average retention time of 0.43 days (range 0–7 days), while the human lenses had an average retention time of 5.46 days (range 0–14 days). The Acuvue Oasys with Hydroclear Plus was retained the longest at 14 days in 2 dogs (average retention 7.67 days), as well as PureVision 2 at 14 days in 2 dogs (average retention 6.0 days). The human lenses had a significantly longer retention time than the veterinary lenses (P < 0.0001). Specifically, Acuvue Oasys with Hydroclear Plus lenses were retained significantly longer than all veterinary lenses and Purevision 2 lenses were retained significantly longer than Keragenix HRT 78 18 mm and Keragenix HydroBlues 18. Conclusions: Although all lenses were easy to use and well tolerated by the dogs, the human lenses were retained longer than the veterinary lenses in dogs. None.

Tear lacritin concentrations in canine keratoconjunctivitis sicca

JL Disney,¹ IP Herring,¹ JP Pickett¹ and RL Mckown²

¹Department of Small Animal Clinical Sciences, Virginia‐Maryland College of Veterinary Medicine; ²James Madison University

Purpose: To determine if tear lacritin concentration is decreased in canine eyes affected by keratoconjunctivitis sicca (KCS). Methods: 58 client‐owned dogs were enrolled in the study (56 eyes without KCS and 54 eyes diagnosed with KCS). All eyes underwent an ophthalmic exam, including Schirmer Tear Testing (STTI), anterior segment assessment, and tear sample collection. Tear samples were evaluated for their total protein concentrations via bicinchoninic acid assay and lacritin concentrations via enzyme‐linked immunosorbent assay. Results: Median total protein of canine tears was significantly increased in KCS‐affected eyes as compared to normal eyes. When measured as a fraction of total tear protein, tear lacritin levels were significantly decreased in KCS‐affected eyes as compared to normal eyes. When measured as a proportion of collected tear volume, tear lacritin concentrations were not significantly different between KCS‐affected eyes and normal eyes. Conclusions: These findings do not support a definitive role of lacritin in canine KCS. Further assessment of tear film lacritin as it relates to other tear protein concentrations and tear volume is warranted. Supported by 4‐VA grant. None.

Evidence of mechanocompensation in the aqueous outflow pathway of non‐human primates with experimental glaucoma

JS Eaton,^1,2 V Raghunathan,^1,2 BJ Christian,³ JT Morgan,² JN Ver Hoeve,^1,4 CC Yang,⁵ H Gong,⁵ CA Rasmussen,^1,4 PE Miller,^1,6 P Russell,^1,2 TM Nork^1,4 and CJ Murphy^1,2,7

¹Ocular Services On Demand (OSOD); ²UC Davis School of Veterinary Medicine; ³Covance Laboratories; ⁴University of Wisconsin‐Madison School of Medicine & Public Health; ⁵Boston University School of Medicine; ⁶University of Wisconsin‐Madison School of Veterinary Medicine; ⁷UC Davis School of Medicine

Purpose: This ex vivo study presents biomechanical and ultrastructural changes in unlasered trabecular meshwork (TM) from non‐human primates (NHPs) with experimental glaucoma (ExGl). Methods: Globes were obtained from n = 16 adult Macaca fascicularis with unilateral ExGl >3 years duration, used in preclinical topical hypotensive drug studies, with drug washout ≥3 months prior to collection. Unlasered TM from ExGl eyes and site‐matched TM from controls were dissected for: elastic modulus (EM) measurement using atomic force microscopy (n = 8 animals); proteomic analysis (n = 7); or confocal light and transmission electron microscopy (TEM, n = 3). Results were correlated to in vivo intraocular pressure (IOP) and retinal nerve fiber layer thickness (RNFLT). Results: In ExGl eyes with RNFLT difference >50%, mean EM was 0.464 ± 0.036 kPa (3.31 ± 0.32 kPa in controls). In ExGl eyes with <5% RNFLT difference, mean EM was 0.151 ± 0.014 kPa (2.63 ± 0.14 kPa in controls). Compared to controls, proteomic analysis in ExGl eyes yielded reduced expression of 11 matricellular proteins; and confocal light microscopy and TEM in ExGl eyes revealed TM thinning, fewer giant vacuoles, and Schlemm's canal narrowing and endothelial cell loss. Conclusions: In ExGl eyes, unlasered TM is biomechanically softened, ultrastructurally thinned and acellular, and matricellular proteins are downregulated. Mechanocompensation of TM may differ from tissue mechanisms in human glaucoma, and may limit this model's utility in studies of therapies targeting the TM. Supported by: Mass. Lions Eye Research Fund & NIH EY022634 (Gong); NIH NEI Core Grant P30 EY016665, Research to Prevent Blindness, & the Retina Research Foundation Catherine & Latimer Murfee Chair (Nork); NIH NEI Grants R01EY019970 & P30EY12576 (Murphy); R01EY019475 & Research to Prevent Blindness (Russell). None.

Effect of 0.5% proparacaine on culture results from dogs, cats, and horses with ulcerative keratitis

SG Edwards,¹ DJ Maggs,² BA Byrne,³ PH Kass⁴ and M Lassaline²

¹Veterinary Medical Teaching Hospital, University of California, Davis, CA, USA; ²Departments of Surgical and Radiological Sciences, University of California, Davis, CA, USA; ³Pathology, Microbiology & Immunology, University of California, Davis, CA, USA; ⁴Population Health & Reproduction, University of California, Davis, CA, USA; ⁵School of Veterinary Medicine, University of California, Davis, CA, USA

Purpose: To investigate effects of topically applied proparacaine on culture results, and to compare cytologic and culture results in patients with ulcerative keratitis. Methods: Corneal samples were collected from 33 dogs, 19 horses, and 12 cats with ulcerative keratitis. Samples for bacterial (dogs, cats, horses) and fungal (horses) culture were collected prior to and following application of 0.5% proparacaine or saline. Cytology samples were then collected following application of 0.5% proparacaine (dogs, cats) or 0.5% tetracaine (horses). Frequency of cultivatable bacteria before and after saline/proparacaine application were compared using Fisher's exact test. Homogeneity of culture and cytology results were assessed using McNemar's test. Results: No difference was detected in number of animals from which bacteria were isolated before and after application of proparacaine (21/37 and 17/37, respectively; P = 0.49) or saline (10/27 and 12/27, respectively; P = 0.78). Small numbers prevented analysis of fungal culture results before and after application of proparacaine (2/12 and 1/12, respectively) or saline (both, 1/8). Considering results from saline and proparacaine treatment groups collectively, bacteria were cultured from 10/20 horses and detected cytologically in 3 of these; fungi were cultured from 3/20 horses and detected cytologically in 2 of these. Bacteria were detected more frequently using culture (31/64) than cytology (17/64; P = 0.005). Conclusions: Proparacaine did not statistically alter bacterial or fungal culture results in this population; however clinical significance warrants investigation. Culture and cytology provided complementary data. Both should be done to maximize organism detection in patients with ulcerative keratitis. Funded by the Center for Companion Animal Health #2014‐54‐R and Center for Equine Health V4S5357, School of Veterinary Medicine, University of California, Davis. None.

The effect of topical latanoprost on aqueous humor flow in normal dogs

KE Fentiman, AJ Rankin and JM Meekins

Department of Clinical Sciences, Kansas State University, Manhattan, KS, USA

Purpose: To evaluate the effect of topical latanoprost 0.005% (Akorn, Lake Forest, IL) on aqueous humor flow rate (AHFR) and intraocular pressure (IOP) in normal dogs. Methods: Following a 5‐day acclimation period, twelve beagles were randomly assigned to 2 groups. On days 1 to 3 and 5 to 9, IOPs were measured 5 times daily in each eye. On days 4 and 10, the anterior chamber and corneal fluorescein concentrations were measured 5, 6.5, and 8 h after topical application of 10% fluorescein (AK‐Fluor^®, Akorn, Lake Forest, IL). On days 5 to 10, one drop of either 0.005% latanoprost or artificial tear solution (Geiss, Destin, & Dunn, Inc., Peachtree City, GA) was applied in each eye twice daily. A crossover study design was used with a one week washout period. Data analysis was performed using repeated measures ANOVA. Results: There was no significant change in IOP in the control group (P = 0.301). In the treatment group, there was a significant decrease in IOP (P < 0.001). In the control group, the mean ± SEM AHFRs on days 4 and 10 were 3.30 ± 0.48 μl/min and 3.21 ± 0.41 μl/min, respectively. In the treatment group, the mean AHFRs on days 4 and 10 were 3.26 ± 0.33 μl/min and 3.87 ± 0.46 μl/min, respectively. Conclusions: Topical 0.005% latanoprost decreases IOP but does not alter the AHFR in normal dogs. Supported by KSU DCS Mark Derrick Canine Research Fund. None.

Feline acute corneal hydrops associated with descemet's membrane rupture: 65 cases

JA Fragola, RR Dubielzig and LBC Teixeira

The Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW), School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA

Purpose: The etiology and pathogenesis of feline corneal hydrops/acute bullous keratopathy (FCH/ABK) has long been the subject of debate. The goal of this investigation was to report clinical and histopathologic findings in 65 cases of FCH/ABK and identify risk factors for the development of FCH/ABK. Methods: Enucleated globes diagnosed with FCH/ABK were identified in the archives of the Comparative Ocular Pathology Laboratory of Wisconsin. Signalment, history, ophthalmic examination findings, and gross and histopathological lesions were reviewed and summarized. The relative risk (RR) of Descemet's membrane rupture in the development of FCH/ABK was calculated. Results: 65 globes from 63 cats diagnosed with FCH/ABK were identified. FCH/ABK was bilateral in 5/63 cats. Descemet's membrane rupture was identified in 51/65 globes. Descemet's membrane rupture was focal in 35/51 globes and multifocal, consistent with Haab's striae, in 16/51 globes. Descemet's membrane rupture was a significant risk factor in the development of FCH/ABK (RR = 107.0, 95% CI [59.8–191.4], P < 0.0001). Additional histologic findings in globes with FCH/ABK included glaucoma (37/65) feline diffuse iris melanoma (13/65), lymphoplasmacytic anterior uveitis (29/65), and buphthalmos (15/65). Conclusions: These findings suggest a causal relationship between Descemet's membrane rupture and FCH/ABK. Except in the cases of Haab's striae, no cause for Descemet's membrane rupture was identified. These findings may support the use of procedures that tamponade Descemet's membrane in the treatment of FCH/ABK. None.

A modified Ahmed glaucoma implant for shunting aqueous humor to the ocular surface in a dog with secondary glaucoma post‐phacoemulsification – case report and proof of concept

EG da Silva

VCA Aurora Animal Specialty Hospital, Aurora, IL, USA

Purpose: Traditional Ahmed gonio‐implant surgeries in dogs are associated with challenges inherent to both maintenance of a patent valve and bleb management. A modification of the standard Ahmed valve has been successfully used to shunt aqueous humor to the ocular surface in a subset of high‐risk human patients after undergoing multiple corneal and filtrative procedures. A 9‐year‐old female spayed Chihuahua‐mix with bilateral refractory glaucoma post‐phacoemulsification had this concept adapted to be used on the remaining eye after unusually fast bleb failure upon standard Ahmed‐valve implantation in the contralateral eye. Methods: A silastic tube (0.76 mm inner diameter, 1.65 mm outer diameter /Dow Corning Corp, Midland, MI) was secured with a simple interrupted 8‐0 nylon suture on the anterior‐lateral surface of an S3 pediatric Ahmed gonio‐implant (New World Medical, Rancho Cucamonga, CA). Following standard placement of the glaucoma drainage device, further sub‐conjunctival dissection allowed the extension tube to be placed and trimmed, exiting through the conjunctiva near the limbus at the level of the 4 o'clock position (OS). The tube was exposed for a few millimeters and this portion was secured with two episcleral simple interrupted 9‐0 nylon sutures to restrict tube movement. In addition to standard post‐operative care for Ahmed glaucoma surgery, twice daily ofloxacin and once daily dorzolamide was prescribed long‐term. Results: The intraocular pressure (IOP) remained <15 mmHg until the 2‐weeks and 6‐weeks after surgery in which clogging of the tube in the anterior chamber was detected and IOP was 25–28 mmHg. On both occasions, anterior chamber cannulation of the glaucoma device was performed under general anesthesia with a 27G needle through a paracentesis; the gonio‐implant was flushed with sterile saline and fluid was immediately seen out of the extension tube over the conjunctiva, characterizing release of the blockage. After each intervention, intracameral tissue plasminogen activator (25ug) and moxifloxacin (0.01 ml) were injected intracamerally. The eye has remained comfortable, normotensive and visual, with IOP < 15 mmHg by the time the abstract was written (14 months post‐operatively). No signs of eyelid discomfort are present at the level of the extension tube. Conclusions: The state of normotension and the lack of bleb formation more than a year after surgery is proof‐of‐concept that the aqueous humor can be successfully shunted to the ocular surface in dogs. Further studies are warranted to evaluate infection rates and the impact of different size/tube materials along with the advantages of using a micro‐pore filter inside the extension tube. None.

Phacoemulsification of a subluxated microphakic lens in the presence of vitreous prolapse with use of Iris Hooks and a capsule tension segment following triamcinolone‐assisted anterior vitrectomy via pars plana – case report

ED da Silva

VCA Aurora Animal Specialty Hospital, IL, USA

Purpose: Vitreous staining, capsule stabilization techniques and anterior vitrectomy via pars plana have gained considerable interest in recent years in human ophthalmology. The purpose of this abstract is to describe a peri‐operative capsule –sparing lens stabilization system with an iris hook and a capsule tension segment (CTS) in the removal of a severely sub‐luxated microphakic lens that was accompanied by vitreous prolapse. Methods: A single‐port pars plana approach to the prolapsed anterior vitreous was chosen using a suture‐less transconjuntival valved 23G trocar (Alcon Laboratories, Fort Worth, TX) inserted 5 mm from the limbus in the dorso‐medial quadrant. The prolapsed vitreous was stained (Triesence^®, preservative free triamcinolone acetonide injectable suspension, Alcon Laboratories, Fort Worth, TX) and subsequently removed via the pars‐plana trocar and using a 2‐handed technique at 2500 cuts per minute. The dangling lens was brought anteriorly and temporarily stabilized with the use of an Ahmed micro‐graspers (MST^® Microsurgical Technology; Redmond, WA) to allow a continuous curvilinear capsulotomy by means of radio‐frequency capsulotomy (Alexos, Oertli Instrumente, Switzerland). Iris hooks (MST^® Microsurgical Technology; Redmond, WA) were used to secure the capsular bag in position for placement of the CTS (FCI Ophthalmics, Pembroke, MA) and subsequently one of which was used to stabilize the CTS, which in turn stabilized the area of zonular loss for the procedure. Surgery was performed using the Alcon Infiniti^® Vision System (Alcon Laboratories, Fort Worth, TX). Energy was delivered strictly in Intelligent‐Phaco (IP) Ozil^® torsional mode. After phacoemulsification was completed, the CTS/iris hook system was removed. The main clear corneal incision was closed with 9‐0 monofilament vycril and the side‐port incisions were closed using stromal hydration. Stained vitreous immediately adjacent to the posterior capsule and aphakic crescent was again removed, via pars plana. The dog was left aphakic. Results: Capsular stabilization was successful, lens removal and anterior vitrectomy was uneventful. No complications such as retinal detachment, recurrence of vitreous presentation or glaucoma were noticed during the first year after surgery. Conclusions: This is the first report of the successful use of an iris hook/CTS system for peri‐operative stabilization of a subluxated lens during phacoemulsification in a dog. None.

Cancer incidence in dogs with clinical presentation of sudden acquired retinal degeneration syndrome—SARDS

SD Grozdanic, H Kecova and T Lazic

Animal Eye Consultants of Iowa, North Liberty, IA, USA

Purpose: To develop diagnostic parameters for differentiation of cancer‐associated retinopathy (CAR) and SARDS in canine population. Methods: Initial diagnosis of SARDS (n = 10, established by referring ophthalmologists based on extinguished electroretinography ‐ ERG) or immune‐mediated retinitis‐cancer associated retinopathy (IMR‐CAR, n = 7) was established in 17 dogs (10 males and 7 females) of different breeds using chromatic pupil light reflex testing (cPLR), ERG), and vision testing by 12 ACVO Diplomates. Previously published criteria for diagnosis of SARDS (Grozdanic et al., Invest Ophthalmol Vis Sci. 2007 Nov;48(11):5178–83) were used to characterize all patients by authors: completely extinguished ERG response (flat ERG), in combination with no pupil response to red (NR) and good response to blue light (GB). IMR was diagnosed based on following criteria: present ERG + NR‐GB PLR, or absent ERG + GR‐GB PLR, or absent ERG + NR‐NB PLR. Four patients did not receive any medical treatment, while 13 were treated with immunosuppressive drugs (cyclosporine, leflunomide, prednisone, mycophenolate, IVIg). Results: None of evaluated patients satisfied previously established criteria for diagnosis of SARDS. Ten patients had completely extinguished ERG responses, while 7 had severe reduction of at least one component of ERG response. Median age of patients was 9 years (range 4.5–14). Sixteen patients were diagnosed with a malignant tumor prior to or at the time of development of visual problems, while 1 was diagnosed with malignant tumor 24 months after initial development of blindness. The most frequent tumors were: meningioma (n = 4), sarcoma (n = 3), pituitary tumor (n = 2), and squamous cell carcinoma (n = 2). Median survival time was 6 months from diagnosis (range 1–36 months). All patients were deceased by May 2017. Most frequent systemic abnormalities were: proteinuria (78%), elevated liver enzymes (47%), and metabolic changes (PU/PD, polyphagia – 24%). Immunosuppressive therapy resulted in the reversal of complete blindness in 44% (4 of 9) of treated patients, with 61% of all treated patients recovering and/or maintaining vision (8/13). Median time for dogs remaining visual was 5 months (range 1–35 months). Conclusions: Previously established parameters for SARDS diagnosis (flat ERG+NR‐GB) have high sensitivity for differentiating true SARDS vs. CAR. A relatively high percentage of patients with CAR responded positively to immunosuppressive therapy. Grants: Sophie's SARDS Research Grant; ISU Biotechnology Funds; VA‐RRD. Conflicts of interest: Vision Biomedical Solutions (Dr. Grozdanic).

Genetic ocular disease prevalence and distribution in 100,000 mixed breed and purebred dogs

C Knox,¹ AM Hughes,¹ J Donner,² H Anderson,² S Davison,³ J Bouirmane,² J Lindqvist,^2,4 B Ganesan,¹ KM Lytle,¹ OP Forman,³ H Lohi^2,5,6,7 and C Cole^1,8

¹Mars Veterinary, Vancouver, WA, USA; ²Genoscoper Laboratories, Helsinki, Finland; ³Mars Veterinary, Waltham‐on‐the‐Wolds, Leicestershire, MA, USA; ⁴Medisapiens, Helsinki, Finland; ⁵Research Programs Unit ‐ Molecular Neurology, University of Helsinki, Helsinki, Finland; ⁶Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland; ⁷Folkhälsan Institute of Genetics, Helsinki, Finland; ⁸Dept of Pathology, University of Florida, Gainesville, FL, USA

Purpose: Describe the disease mutation prevalence for specific inherited ophthalmic disorders, comparing mixed‐breed and purebreds, using the largest canine genetic cohort ever studied. Methods: A custom Illumina^® Infinium HD genotyping bead chip targeting known mutations was used to test 83,220 mixed‐breed dogs (predominantly US) and 18,102 purebred dogs and wild canids (333 breeds/species, several countries) using DNA from cheek swab and blood samples. 152 known Mendelian disease variants were investigated, including 29 recessive and 2 dominant ophthalmic risk markers. Quantitative disease prevalence estimates were reported between the two groups. Results: Of 31 ophthalmic disease variants evaluated, 28 were observed at least once. Most disease variants observed were encountered in both mixed breed and purebred dogs (78.6%), while others were observed in only one of the groups. Five ocular disease variants were found in 32 breeds in which they were not previously described. The allele frequencies of 14 ophthalmic disorders were higher in mixed‐breeds than in purebreds. Conclusions: Genetic ophthalmic disorders are common in both purebred and mixed‐breed dogs. The proportion of dogs carrying at least one of the screened ocular disease variants is significantly higher in mixed breeds than in purebred dogs (19.8% vs. 9.8%, respectively). Mixed breeds were more likely to carry a recessive disorder, but purebreds were more likely to be genetically affected. These findings indicate the importance of considering many genetic disorders as potential causes of ophthalmic disease in pure and mixed‐breed dogs due to wider breed prevalence and/or common breed ancestry than previously thought. Research funded by Mars Veterinary and Genoscoper Laboratories. HL, I. JD, HA, JB, JL, SD, AH, BG, KL, OF, and CC, E.

In vivo characterization and distribution of retinal folds in normal and oculo‐skeletal dysplasia carrier dogs

S Iwabe,¹ D Holle,² J Cohen,² K Anneback,² WA Beltran¹ and GD Aguirre¹

¹Section of Ophthalmology, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA; ²The Seeing Eye Inc., Morristown, NJ, USA

Purpose: To analyze the structure and pattern of distribution of retinal folds in normal and oculo‐skeletal dysplasia carrier dogs. Material and methods: Two mix‐breed drd2 carriers (2 months‐old), 1 Labrador drd1 carrier (14 months‐old) and 2 normal German Shepherd dogs with retinal folds (15–17 months‐old) were studied. In‐vivo retinal microanatomy was evaluated under general anesthesia by non‐invasive imaging with cSLO/sdOCT. The 2 drd2 carrier dogs were culled for histology and immunohistochemistry (RHO, cone arrestin and RPE) immediately after in vivo imaging. Results: The drd carrier dogs presented multiple branching retinal folds that radiated from the region in the central tapetal fundus in close proximity to the superior retinal vessels. Normal dogs presented a single incomplete ring of retinal folds, multiple linear folds or a combination of both. Retinal findings were not perfectly symmetrical in both eyes in drd‐carrier or normal dogs. In all lesions, near‐infrared and red‐free images revealed the lesions as grey dark streaks in the tapetal area but no fluorescence was observed in AF mode. sdOCT B‐scans of lesions showed retinal folds with no other retinal abnormalities. H&E sections confirmed retinal morphology as observed in the sdOCT in vivo images. IHC sections confirmed immunoreactivity of photoreceptors in the retinal folds detached from the normal RPE layer. Conclusion: Retinal folds present in normal and drd carrier have the same in vivo microanatomic features. However, the location and pattern of fold distribution is random in normal dogs, but specifically located near the central, superior retinal vessels in drd carrier. This study was supported in part by FFB and NEI. None.

When should we measure the schirmer tear test?

H Iwashita, S Wakaiki, Y Kazama and A Saito

Triangle Animal Eye Clinic. Tokyo, Japan

Purpose: Although the Schirmer tear test‐1 (STT) effectively evaluates aqueous lacrimal secretion, the strip may influence tear film break up time (TFBUT) and the appearance of the fluorescein‐stained cornea. However, performance of fluorescein staining before the STT may affect STT results. To the authors’ knowledge, the effect of fluorescein application on the STT result has not been reported in dogs. Methods: Dogs presented to Triangle Animal Eye Clinic were divided into 3 groups based upon STT result ‐ Group 1: <5 mm/min, Group 2: 5–10 mm/min, and Group 3 > 10 mm/min. All dogs underwent STT‐1 measurement, followed by application of 0.5 μl/eye of fluorescein into the inferior palpebral conjunctival fornix. Following 10 min to permit tear turnover, a second STT‐1 measurement was recorded. Results: A total of 61 eyes (31 right eyes, 30 left eyes) from 33 dogs (11 males, 22 females) with a mean ± SD age of 7.7 ± 3.9 years were included in this study. Mean ± SD pre‐fluorescein STT results for Groups 1, 2, and 3 were 2.2 ± 1.3, 7.0 ± 2.2, and 19.8 ± 4.4 mm/min, respectively. For the same 3 groups, mean ± SD post‐fluorescein STT were 3.5 ± 1.9, 7.6 ± 4.9, and 19.4 ± 3.6 mm/min. There was no significant difference between pre‐ and post‐fluorescein STT results within each group (P = 0.091, 0.57, 0.43, respectively; paired t‐test). Assessment of corneal fluorescein staining patterns was adequate in all eyes. Conclusions: Application of 0.5 μl fluorescein 10 min previously did not change the STT result in dogs. None.

The effect of subconjunctival bupivacaine, lidocaine, and mepivacaine on corneal sensitivity in healthy horses

MR Jinks, RL Fontenot, RW Wills and CM Betbeze

College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA

Purpose: To compare the efficacy and duration of effect of three local anesthetics on corneal sensitivity when administered subconjunctivally in horses. Methods: Eight healthy horses were used in a randomized, masked, crossover study with two‐week washout periods between trials. The subconjunctival space of the randomly selected eye was injected with 0.2 ml of bupivacaine (0.5%), lidocaine (2%), mepivacaine (2%), or saline. All horses received each medication once in the selected eye. The contralateral eye served as a control. The corneal touch threshold (CTT) was measured in both eyes with a Cochet‐Bonnet esthesiometer prior to sedation with xylazine, after sedation, and at 10 min intervals after subconjunctival injection until corneal sensitivity returned to baseline. The total time of decreased CTT and the maximum decrease in CTT were compared for each medication using a general linear mixed model (P < 0.05). Results: Total time of decreased CTT was 103.8 min for lidocaine, 105.0 min for bupivacaine, 138.8 min for mepivacaine and 7.5 min for saline. All local anesthetics decreased CTT significantly longer than saline (P < 0.01) and mepivacaine decreased CTT longer than lidocaine (P = 0.04). Maximal CTT reduction was 3.63 cm for bupivacaine, 3.94 cm for lidocaine, and 4.75 cm for mepivacaine, which were all significantly greater (P < 0.01) than saline (0.56 cm). No evidence of corneal toxicity was noted with any medication. Conclusion: Subconjunctival injections of lidocaine, bupivacaine, and mepivacaine effectively reduced corneal sensitivity in horses and can be considered for perioperative analgesia for equine corneal procedures. Supported by MSU‐ORGS House Officer Clinical Research Grant. None.

Comparison of single vs. averaged triplicate intraocular pressure measuments in dogs

CR Kennedy,¹ EH Hofmeister² and KA Diehl¹

¹College of Veterinary Medicine, University of Georgia, Athens, GA, USA; ²College of Veterinary of Veterinary Medicine, Midwestern University, Downers Grove, IL, USA

Purpose: To retrospectively compare single and mean triplicate applanation tonometry readings across four previously conducted intraocular pressure measurement studies. Methods: Data from four previously conducted studies evaluating the effect of anesthetic protocols on intraocular pressure were compiled. Baseline measurements (before treatment) for all dogs, as well as combined data (all time points of all studies) were statistically analyzed with paired t‐tests. Repeated measures ANOVA and post‐hoc comparisons were performed for each study to evaluate for differences between single and mean triplicate measurements, right versus left eyes, and the effect of treatment and time on the data. Results: Statistically significant difference between single and mean triplicate measurements was inconsistent across the analysis. Mean differences between the two groups were less than 0.3 mmHg for all data sets. The standard deviation for single measurements was significantly higher compared to mean triplicate measurements for all groups. Conclusion: Results indicated that single intraocular pressure values did not differ in a clinically significant magnitude from the average of triplicate readings across multiple studies. Variability of single measurements was higher compared to the mean of triplicate readings. Triplicate measurements would only be beneficial in situations where intraocular pressure is expected to be widely variable. None.

Comparison of serum, EDTA, tetracyclines and N‐acetylcysteine for inhibiting collagenase activity in an in vitro corneal degradation model

BA Kimmitt,¹ GE Moore² and J Stiles¹

¹Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA; ²Veterinary Administration Department, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA

Purpose: To compare the efficacy of serum, various concentrations of EDTA, tetracyclines, and N‐acetylcysteine, alone and in combination, for prevention of corneal degradation in vitro. Methods: Corneas were harvested from dogs and horses euthanized for non‐ocular reasons. Serum from healthy donors was pooled. Serum, EDTA (2%, 1%, 0.3%), tetracycline, doxycycline, minocycline (1%, 0.5%, 0.1%), or N‐acetylcysteine (5%, 1%, 0.5%) was evaluated in the assay alone or in combination. Inhibition of clostridial degradation was assessed by evaluating corneal weight loss. Results: For canine samples, 0.5% and 1% tetracycline, doxycycline and minocycline were significantly more effective than their 0.1% counterpart (P ≤ 0.010, P ≤ 0.0077, P < 0.0001, respectively). For equine samples, 0.5% and 1% tetracycline and doxycycline were significantly more effective than 0.1% (P < 0.0001 for both). In both canine and equine samples, concentrations of tetracyclines ≥0.5%, EDTA ≥0.3%, and N‐acetylcysteine ≥0.5% were more efficacious than serum (P < 0.0027 for canine compounds; P < 0.0001 for equine compounds) in preventing corneal weight loss. 0.5% tetracycline and 1% EDTA were as or more efficacious alone than when in combination with another compound. Conclusions: Concentrations of tetracyclines ≥0.5%, EDTA ≥0.3%, and N‐acetylcysteine ≥0.5% were efficacious in preventing corneal weight loss in an in vitro model as compared to the positive control. These concentrations were also more efficacious than homologous serum. Tetracycline 0.5% and EDTA 1% were equally as efficacious alone as when in combination with another compound. None.

Targeting gene expression to the canine aqueous humor outflow pathways via intravitreal vector administration

AM Komaromy,¹ KL Koehl,¹ CD Harman,¹ BR Ksander,² M Gregory‐Ksander,² VA Chiodo,³ A Marshak‐Rothstein,⁴ P Busto,⁴ SL Boye,³ WW Hauswirth³ and SE Boye³

¹Michigan State University (MSU); ²Harvard Medical School; ³University of Florida; ⁴University of Massachusetts Medical School

Purpose: A main goal of our research efforts is the long‐term control of intraocular pressure by adeno‐associated virus (AAV) mediate gene therapy in dogs with open‐angle glaucoma. In this study we compared green fluorescent protein (GFP) expression levels along the canine aqueous humor (AH) outflow pathways following intravitreal (IVit) vs. intracameral (IC) vector administration. Methods: AAV2‐GFP (either self‐complementary with B6‐PI promoter, or single stranded with Y444F capsid mutation and smCBA promoter) was injected in 12 eyes of 6 young adult wild‐type dogs either IC (n = 8 eyes) or IVit (n = 4 eyes). Total number of vector genomes (vg) injected were 2.78e12–5.56e13 vg (IC) or 2.1e11–2.78e12 vg (IVit). GFP expression was visualized and quantified (ImageJ) histologically at 5 weeks by epifluorescent microscopy. Results: Histologic examination showed that IC delivery resulted in strong GFP expression along the AH outflow pathways, including the trabecular meshwork (TM). This expression resulted in clinically detectable fluorescence within the iridocorneal angle (RetCam; Clarity Medical Systems). IVit delivery of AAV2‐GFP resulted not only in the expected transduction of retinal cells, but also the ciliary and iris epithelium and, surprisingly, AH outflow pathways. GFP expression levels within the TM were comparable between IC and IVit delivery when using the same vector doses. Conclusion: In dogs, IVit injection of therapeutic agents, such as gene therapy vectors, allows targeting of both anterior and posterior segments of the eye. This is in contrast to IC injection that mostly targets the anterior segment. Supported by NIH Grants EY025752, EY024280, P30EY021721, R01EY024280, Glaucoma Research Foundation, BrightFocus Foundation, Research to Prevent Blindness, Foundation Fighting Blindness, Edward Sheppard and family, MSU Discretionary Funding Initiative. None.

Vitreous degeneration and associated ocular abnormalities

H Krishnan,¹ K Diehl² and GD Aguirre¹

¹School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA; ²College of Veterinary Medicine, University of Georgia, Athens, GA, USA

Purpose: Vitreous degeneration (VD) is a common finding in Italian Greyhounds (IG) and several other dog breeds. Although there is concern about the significance of this finding, there is no documentation about either the frequency of VD or its association with ocular co‐morbidities such as cataracts, lens luxation, glaucoma and retinal detachment. Methods: Results from breed screening ophthalmic examinations performed by ACVO diplomates and submitted to the Companion Animal Eye Registry (CAER) from 2013 through 2016 were obtained. We selected IG in which vitreous degeneration is commonly diagnosed; data for the Greyhound breed served as negative control. Additional breeds were Shih Tzus, Affenpinschers, Bichon Frises (BF), and Brussels Griffons (BF). Data analyzed included age, number of examinations, and whether VD, along with cataracts, lens luxation, glaucoma and/or retinal detachment were present in either or both eyes. Results: IG had the highest frequency of VD‐affected dogs (30%); 19% of these had cataracts, but 7.4% of dogs had cataracts and no VD. Greyhounds did not have VD, and cataracts were found in 14% of examined dogs. BF and BG breeds had a comparable incidence for VD and cataracts as IG. The incidence of VD and cataracts appeared to increase with age, although sampling was not uniform for all ages. Conclusions: VD is commonly found in IG and other breeds, and incidence increases with age. Although cataracts are present in VD‐affected dogs, they also occur in eyes without VD. There appears to be no association between VD and lens luxation, glaucoma and detachment. Supported by Van Sloun Fund for Canine Genetic Research. None.

Microsurgical training in ophthalmology and veterinary ophthalmology residency training programs

M Lassaline,¹ DJ Maggs¹ and KA Boudreaux²

¹Department of Surgical & Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA; ²Academic Programs, School of Veterinary Medicine, University of California‐Davis, Davis, CA, USA

Although current graduate medical education models espouse criterion‐based training, microsurgical training has traditionally followed an apprenticeship model. Current methods of microsurgical training in ophthalmology have not been well defined. Purpose: To describe microsurgical training methods in ophthalmology (OPH) and veterinary ophthalmology (VOPH) residency training programs (RTPs). Method: An online survey designed to describe the use of non‐patient training tools (inanimate objects, cadavers, simulators) and identify criteria for assessment of microsurgical skills was distributed to 99 OPH and 35 VOPH RTP directors. Results: Analysis was based on surveys returned from 11/99 physicians (11%) and 18/35 veterinarians (51%). More responding physicians (100%) than veterinarians (56%) were employed in academia relative to private practice (P = 0.03). Median number of ophthalmologists per practice, ophthalmologists training residents per practice, and residents per RTP were significantly greater for OPH (25, 14, 12, respectively) than VOPH (3, 3, 2, respectively; all P < 0.001). Non‐patient training tools were used for microsurgical training in 97% RTPs. Significantly more OPH (73%) than VOPH (0%) RTPs used surgical simulators (P < 0.001). RTPs employed direct observation (97%) more than videotaping (21%) of resident's non‐patient microsurgical practice. Level of skill acquisition was cited more often than time in RTP or number of surgeries to determine when residents should perform patient microsurgery (79% skill, 28% time, 21% number) and to assess success of microsurgical training (90% skill, 17% time, 48% number). Conclusion: OPH and VOPH RTPs are similar in their use of training tools and evaluation of microsurgical skill acquisition. None.

Infectious ocular disease severity varies by pathogen detected in cats

AC Lewin,^1,2 C Longhurst,³ GJ McLellan,^1,2,4 CR Brandt,^2,4 AW Kolb,⁴ KA Bernard,¹ SP Newbury¹ and E Bentley^1,2

¹School of Veterinary Medicine, University of Wisconsin‐Madison, Madison, WI, USA; ²McPherson Eye Research Institute, University of Wisconsin‐Madison, Madison, WI, USA; ³Department of Biostatistics and Medical Informatics, University of Wisconsin‐Madison, Madison, WI, USA; ⁴School of Medicine and Public Health, University of Wisconsin‐Madison, Madison, WI, USA

Purpose: To identify pathogens using PCR and viral isolation in shelter cats with ocular and upper respiratory disease, and to identify factors associated with increased severity of clinical disease. Methods: Oropharyngeal swabs from 90 cats in 11 animals shelters across the USA were obtained and tested by RT‐PCR using a feline respiratory panel after clinical scoring for ocular and respiratory disease. A multivariable linear mixed model assessed the relationship between clinical scores and age, sex and pathogen. Viral isolation was performed on all samples, prior to DNA extraction and gel electrophoresis using 42/90 isolates. Results: Five pathogens were detected at variable frequency by PCR: feline calicivirus (FCaV) (63%), feline herpesvirus (FHV‐1) (54%), Mycoplasma felis (51%), feline coronavirus (17%) and Chlamydophila felis (3%). A positive FHV‐1 PCR result was associated with higher respiratory scores (95% CI = (0.050–1.351), P < 0.05) and lower ocular scores (95%CI = (−2.464, −0.597), P < 0.01). Viral isolation detected virus in 84/90 samples within 7 days. Only 3/21 virus isolates from samples obtained from cats that had both FHV‐1 and FCaV detected by PCR showed banding consistent with FHV‐1 on electrophoresis after DNA extraction. Conclusion: FHV‐1 was associated with higher respiratory scores, but lower ocular scores, which warrants further research. The results of the viral isolation and electrophoresis suggest that FCaV may grow preferentially over FHV‐1 in vitro. Overall, the results indicate that FCaV may play a role in infectious ocular disease in cats housed in animal shelters. Supported by the UW‐Madison Companion Animal Fund, UW‐Madison Shelter Program, Research to Prevent Blindness and NIH grants EYP30016665 and UL1TR000427. None.

Effect of immediate postoperative intracameral tissue plasminogen activator (TPA) on anterior chamber fibrin formation in dogs undergoing phacoemulsification

LA Mancuso, B Nadelstein, A Berdoulay and RA Spatola

Animal Eye Care of Chesapeake

Purpose: To evaluate the effect of intracameral tPA (alteplase, Stokes Pharmacy, Mount Laurel, NJ), administered at immediate conclusion of phacoemulsification, on postoperative anterior chamber fibrin formation in dogs. Methods: Thirty dogs undergoing bilateral phacoemulsification (60 eyes) were administered 25 μg/0.1 ml intracameral tPA in one eye and 0.1 ml unmedicated aqueous vehicle in the contralateral eye immediately after incision closure. Experimental and control eyes were randomly assigned. Intraocular pressure (IOP) was measured, and corneal edema, posterior capsular opacification (PCO), pigment precipitates on the intraocular lens (IOL) implant, aqueous flare, and fibrinous effusion graded (0 to +4) after anesthetic recovery and at 1 week, 2–3 weeks, 4–6 weeks, 8–12 weeks, and greater than 12 weeks postoperatively. Examiners were masked throughout surgery and follow‐up. Results: 50% of dogs (15/30) developed some degree of anterior chamber fibrin in one or both eyes after phacoemulsification (9 unilateral, 6 bilateral). 33.3% (10/30) of tPA‐treated eyes developed fibrin compared to 36.7% (11/30) of control‐treated eyes. Within three weeks after phacoemulsification, 60% of dogs (18/30) experienced some degree of postoperative ocular hypertension (POH) in one or both eyes (9 unilateral, 6 bilateral). 50% (15/30) of tPA‐treated eyes experienced POH compared to 40% (12/30) of control‐treated eyes. Conclusions: Administration of intracameral tPA at immediate conclusion of phacoemulsification in dogs had no effect on the incidence of anterior chamber fibrin formation or POH in the early postoperative period. None.

Intraocular pressure, central corneal thickness and conjunctival microbiota in adult white‐tailed deer (Odocoileus virginianus)

T Villar,¹ AL Pascoli,^2,3 F Ramsey,¹ E Capistrano,¹ CF Shipley,¹ KM Smith‐Fleming¹ and BC Martins¹

¹Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign, IL, USA; ²College of Veterinary Medicine, São Paulo State University, Jaboticabal, SP, Brazil; ³College of Veterinary Medicine, Regional University of Blumenau, Blumenau, SC, Brazil

Purpose: To determine the normal values for intraocular pressure (IOP) and central corneal thickness (CCT) as well as the normal conjunctival microbiota during winter and spring in healthy adult white‐tailed deer (Odocoileus virginianus). Methods: Eight adult white‐tailed deer were anesthetized and examined. Conjunctival samples were collected from the lower conjunctival fornix using sterile swabs and submitted for aerobic bacterial and culture and susceptibility testing as well as fungal culture. IOP was bilaterally measured by applanation (TonoPen^®) and rebound (TonoVet^®) tonometry. Central corneal thickness (CCT) was measured by ultrasound pachymetry. Statistical comparison analyzed differences between eyes, tonometers and seasons by analysis of variance (ANOVA). Results: Mean IOP was 19.67 ± 2.25 mmHg (TonoPen^®) and 15.0 ± 3.69 mmHg (TonoVet^®). There were no significant differences in IOP measurements between eyes or seasons (P > 0.05) with both tonometers. Applanation tonometry had significantly higher values compared to rebound tonometry in both seasons (P < 0.0004). Mean CCT was 747.78 ± 43.88 μm with no significant difference in values between eyes or seasons (P > 0.79). The most prevalent bacterial genera identified were Bacillus, Corynebacterium, Arthrobacter and Actinomyces in both seasons. Growth of Staphylococcus sp. was only observed in winter. A single fungal genus was cultured in winter (Scedosporium) while four were isolated in spring (Fungi sp., Cladosporidium, Scopulariopsis, Debarymuces). Conclusions: The study was able to describe and compare the normal parameters of IOP and CCT as well as normal ocular surface microbiota in white‐tailed deer in the winter and spring. None.

Stromal keratitis presumed to be herpetic in 10 cats: 2009–2017

TL McCalla¹ and DJ Maggs²

¹Animal Eye Care, Bellingham, WA, USA; ²Department of Surgical and Radiological Sciences, University of California, Davis, CA, USA

Purpose: To characterize feline stromal keratitis presumed to be herpetic. Methods: Medical records were reviewed and owners were interviewed regarding cat temperament, stressors, and apparent pain. Perceived pain was also assessed clinically and scored semiquantitatively. Results: Ten cats (13 eyes) met entry criteria. Seven were male and 3 were female. Seven cats were affected unilaterally. Median (range) age was 10.2 (0.4–14.8) years but 7/10 were >9 years. Median (range) disease duration prior to referral was 5.5 (2–52) weeks but ≤16 weeks in 9/10. All cats were assessed as having 2–6 stressors/intercurrent diseases. Pain was assessed as absent (2 cats), mild (1), moderate (4), or severe (3). Corneal lesions at presentation included vascularization (7 cats), ulcers/erosions (6), bullae (6), stromal edema (5), fibrosis/scarring (3), or sequestrum (1). Although treatment was tailored to individual cats, frequently used treatments included famciclovir (8 cats), topical cidofovir (9), hyaluronate (9), moxifloxacin (4), and (if corneal erosions were absent) topical prednisolone acetate (8). Complementary/alternative medical therapies (CAMT) used included stress reduction (10 cats), pheromone therapy (4), L‐lysine (5), and proprietary supplements (6). All medications except CAMT were stopped in 2 cats (2 eyes); 8 cats (11 eyes) remained on some medications and CAMT for the entire follow‐up period (1.4–11 months). Conclusions: Famciclovir, in combination with topically administered antibiotics, hyaluronate, and judicious use of corticosteroids is effective for treatment of presumed herpetic stromal keratitis in cats. Simultaneous recognition and relief of pain and stressors is likely also important. None.

Comparative tests of canine tear film status using the I‐strip tear test and the Schirmer tear test

TR Miller,¹ I Hofmann² and J Dunbar³

¹Tampa Bay Veterinary Specialists, Largo, FL, USA; ²i‐Med Pharma, Montreal, QC, Canada; ³University of New Brunswick, Fredericton, NB, USA

Purpose: To assess the use of meniscometry, as measured by the i‐strip tear test (ITT) and compare it to the Schirmer tear test (STT), for the assessment and diagnosis of tear film abnormalities in dogs. Methods: ITT and STT were performed in paired samples in 205 eyes of 105 dogs undergoing routine ophthalmic examination. ITT was measured prior to STT in all eyes, with at least a 5 min interval between tests. Dogs with both keratoconjunctivitis sicca (KCS) and non‐KCS conditions were included in the study, and were clinically assessed as to whether they had signs of KCS at the time of examination. Correlation between ITT and STT, and both ITT and STT with clinical diagnosis were assessed by Cohen's kappa test. Results: 105 dogs were tested, representing 31 different breeds, and ranged in age from 4 months to 18 years. 56 dogs were diagnosed with KCS at the time of the exam, or had a previous history of KCS. ITT values ranged from 0 to 20 mm/5 s. STT ranged from 0–30/60 s. ITT values of 5 mm or higher, and STT values of 15 mm or higher were considered a normal test result. The presence of a normal or abnormal ITT and STT were correlated with the presence or absence of clinical signs. ITT had 98% sensitivity and 98% specificity in predictive value for clinical diagnosis. STT had 96% sensitivity and 94% specificity in predictive value for clinical diagnosis. ITT and STT were not statistically different (.655, 95% CI: .535‐.775). However, ITT had a greater agreement of correlation with clinical signs (.880, 95% CI: .804‐.956) than STT (.660, 95% CI: .542‐.778). Conclusions: The ITT is an easily performed assessment of the canine tear film, and may correlate with clinical signs as well or better than the STT. E (I Hofmann).

Alternative splicing in CEP290 mutant cats results in a milder phenotype than LCA^CEP290 patients

AL Minella,¹ K Narfström² and SM Petersen‐Jones¹

¹Comparative Ophthalmology Laboratory, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; ²Department of Medicine and Surgery, College of Veterinary Medicine, University of Missouri – Columbia, Columbia, MO, USA

Purpose: Leber Congenital Amaurosis (LCA) is a devastating childhood‐onset blindness. The most common gene implicated is the CEP290 gene, which encodes a protein integral for transport of proteins between photoreceptor inner and outer segments. The CEP290 mutant cat harbors an intronic mutation that introduces a splice donor site and is predicted to result in a frameshift, premature stop codon, and protein truncation. This results in a milder phenotype than typical for LCA^CEP290 patients. We hypothesize that this is due to only partial use of the novel splice site resulting in the presence of sufficient wild‐type protein to partially preserve the phenotype. Methods: RNA and protein was extracted from retinas of nine cats; three from each genotype (mutant, heterozygous, and wild‐type). TaqMan qRT‐PCR assays were used to compare wild‐type and truncated transcript levels. Relative protein abundance was analyzed by western blot. Eyes from four CEP290 mutant felines were labeled for CEP290 protein using immunohistochemistry. Results: CEP290 mutant cats show low‐level (17.4% of wild‐type cats) use of the wild‐type splice site as well as usage of the mutant splice site. Protein analysis shows presence of CEP290 protein that likely compromises a combination of both wild‐type and truncated protein and that localizes correctly. Conclusions: The milder phenotype of CEP290 mutant cats is due to presence of functional CEP290 protein. This includes a low but significant level of full‐length wild‐type protein and likely also truncated protein that we predict retains some function. Funded by The Myers Dunlap Endowment to Dr. SM Petersen‐Jones, The Grousbeck Family Foundation, CVM Center for Feline Health and Well‐Being, and the Cotter Endowment. None.

Clinical efficacy of a new quick tear volume measurement in dogs: strip meniscometry

K Miyasaka,¹ Y Kazama,² H Iwashita² and A Saito²

¹Echo Electricity Co., Ltd., Tokyo, Japan; ²Triangle Animal Eye Clinic, Tokyo, Japan

Purpose: To introduce a new quick lacrimal test (termed Strip Meniscometry), and to evaluate its clinical efficacy for dogs. Methods: This study involved 1265 eyes of 641 subject dogs randomly selected among the outpatients having various corneal disorders. Each subject underwent the strip meniscometry test (SMT) using SMTube (Echo Electricity Co., Ltd.), the phenol red thread test (PRT) using Zone Quick (Showa Yakuhin Kako Co., Ltd.) and the Schirmer tear test (STT). All examinations were performed in the above‐described order without topical anesthesia. Results: Mean values of the tests resulted in 33.16 ± 8.39 mm/15 s for PRT, 16.37 ± 6.74 mm/60 s for STT, and 9.52 ± 4.04 mm/5 s for SMT, respectively. Statistically significant correlations were found for all pairs among PRT, STT and SMT. The Pearson's correlation coefficient r was 0.613 for a pair of PRT‐STT, 0.571 for PRT‐SMT, and 0.668 for STT‐SMT, respectively. When the tear deficiency was defined by the STT score <15 mm/60 s, the maximal clinical efficacy of SMT was obtained at the cut‐off length = 10 mm/5 s. Conclusions: The result of SMT examination was well‐correlated with the results of STT and PRT. The cut‐off length of SMT for tear deficiency in dogs was suggested in reference to the standard STT results. None.

An investigation of the factors maintaining proliferative capacity of canine corneal epithelial cells

M Morita, N Fujita, K Saeki, K Hayashimoto, T Nakagawa, R Nishimura and K Tsuzuki

Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan

Purpose: We have previously reported that canine corneal epithelial cells (CECs) maintain the proliferative capacity without using feeder cells or growth factors unlike other species. The purpose of this study was to investigate the factors of maintaining prominent proliferative capacity of canine CECs comparing with rabbit CECs. Methods: Canine and rabbit CECs harvested from limbus were cultured without using feeder cells and growth factors. The proliferative capacity and the ratio of Ki‐67 positive cells were compared and both CECs were passaged continuously until the growth arrest. Canine and rabbit CECs were then cultivated with conditioned media of each other's cells. cDNA microarray and qPCR analyses were performed and the gene expressions of soluble factors in both CECs were also compared. Results: Canine CECs showed higher proliferative capacity and could be passaged more times than rabbit CECs. Conditioned media of canine CECs tended to promote the proliferation of rabbit CECs, while that of rabbit CECs inhibited the proliferation of canine CECs. Epidermal growth factor (EGF) receptor ligands, such as neuregulin 1 (NRG1) and heparin‐binding EGF‐like growth factor (HB‐EGF) were highly expressed in canine CECs than in rabbit CECs. Conclusions: It is suggested that canine CECs secrete growth promoting factors and EGF receptor ligands are their possible candidates. However, it is also suggested that canine CECs do not secrete growth inhibitory factors which are secreted by rabbit CECs. Further studies are needed to clarify the mechanism of maintaining proliferative capacity of canine CECs from these two perspectives. Supported by Grant‐in‐Aid for Scientific Research (C) 26450422. None.

Utility of a simple, inexpensive retinal model for teaching of ophthalmoscopy to veterinary students

FM Mowat, G Druley and HD Westermeyer

College of Veterinary Medicine, North Carolina State University

Purpose: Difficulty in mastering the techniques of ophthalmoscopy in veterinary education is compounded by challenges of live animal examination. We sought to explore the utility of practice with an inexpensive teaching model as a method to improve technique and skill in ophthalmoscopy of first‐year veterinary students. Methods: The study was approved by the NCSU Institutional Review Board. Different point lettering, readable using three methods of ophthalmoscopy (direct, panoptic and indirect) was placed in 2 oz. canisters with 8 mm pupil apertures. Half of the students in a veterinary teaching course practiced with models for 20 min in addition to live animals, the other half spent a similar amount of time with live animals only. Opinion surveys of the model, and examination grades for indirect ophthalmoscopy were anonymously collected from students. Odds ratio was calculated for examination success (Sigma Plot v.11, Systat Software Inc). Results: 49 students practiced with the model, of these 15 students completed the final examination; 51 students did not practice with the model, and of the these, 17 completed the final examination. 71.4% of students felt the models were easy to use, 100% thought that model use should continue for future classes. Students that used the models were 7 times more likely to pass the examination than students that had not (P = 0.035). Conclusions: We describe an inexpensive, versatile teaching model for veterinary students that is well liked and results in significantly better technical performance of indirect ophthalmoscopy under examination conditions.

Conflicts of interest: none.

Clinical findings in a case‐control study of dogs with sards, age and breed‐matched controls, and dogs with pituitary dependent hyperadrenocorticism

A Oh, ML Foster, KF Lunn and FM Mowat

College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Purpose: Sudden acquired retinal degeneration syndrome (SARDS) is characterized by retinopathy and systemic clinical abnormalities. Our objective was to compare clinical parameters in SARDS cases with those from age‐ and breed‐matched normal controls, and cases of pituitary‐dependent hyperadrenocorticism to further examine SARDS within the ageing and endocrinopathy clinical spectra. Methods: 12–15 dogs of each group (early SARDS, matched controls, hyperadrenocorticism) were recruited to North Carolina State University for examination. Parameters assesed included clinical examination, serum chemistry, complete blood count, urinalysis and optical coherence tomography. Statistical analysis was performed using one‐way ANOVA with a Bonferroni post‐test and significance of P < 0.05. Results: Compared with normal dogs, dogs with SARDS had significantly higher body condition score, elevated total white cell and neutrophil counts, elevated plasma and serum proteins (total protein, albumin, globulin) and elevated serum calcium values. Compared with dogs with pituitary‐dependent hyperadrenocorticism, dogs with SARDS were younger, had significantly lower liver enzyme values (ALP, GGT), lower baseline and post‐ACTH cortisol values, lower serum phosphorous and higher serum albumin and urine specific gravity. The outer nuclear layer was significantly thinner in dogs with early SARDS compared with both control groups in all 4 measured quadrants (dorsal, ventral, nasal and temporal). Multifocal small low‐lying retinal detachments were identified in dogs with SARDS. Conclusions: Significant differences were identified in clinical parameters of SARDS dogs compared with both age‐ and breed‐matched controls and dogs with hyperadrenocorticism. These differences in may provide future utility for early diagnosis of SARDS prior to vision loss. Supported by VAFSARDS2015. None.

Effect of telmisartan on IOP, blood pressure and ocular perfusion pressure in a spontaneous feline glaucoma model

K Oikawa,^1,2 JA Kiland,² C Wickland,² S Neufcourt² and GJ McLellan^1,2

¹Department of Surgical Sciences, School of Veterinary Medicine; ²Ophthalmology & Visual Sciences, School of Medicine and Public Health

Purpose: To determine the effect of an angiotensin receptor blocker (ARB) on ocular perfusion pressure (OPP) in cats with feline congenital glaucoma (FCG). Methods: Nine cats with FCG (3 female; 6 male) and 11 normal cats (2 female; 9 male) were studied under a protocol approved by the Institutional Animal Care and Use Committee. IOP was measured by rebound tonometry and blood pressure (BP) including systolic, diastolic and mean arterial pressure readings (SBP, DBP and MAP, respectively) were obtained by oscillometric method. Telmisartan (1 mg/kg/day PO) was administered to cats with FCG. Cats were acclimated to measurements, and baseline IOP and BP were obtained for 5 weeks prior to treatment. Mean ocular perfusion pressure (MOPP) was calculated (MOPP = 2/3×MAP‐IOP). Mean values in FCG were compared between time points over the study period as well as to age‐matched normal cats (ANOVA with Tukey‐Kramer multiple comparisons post‐test; P‐value < 0.05 considered significant). Results: In FCG cats, baseline mean [SD] IOP (28.9 mmHg [6.3], P < 0.001) was significantly higher and MOPP (38.5 mmHg [8.1], P < 0.001) was significantly lower than normal (16.5 mmHg [2.4] and 51.4 mmHg [7.0], respectively). Mean IOPs in both eyes in FCG were consistently higher than control over the study period (P < 0.01). No significant changes in BP or OPP were detected in telmisartan‐treated cats over the study. Conclusions: Telmisartan was well tolerated and did not have a detrimental effect on OPP in cats with glaucoma. Supported by the UW‐Madison Companion Animal Fund; Bright Focus Foundation; NIH grant P30 EY0016665, and an unrestricted award to the Department of Ophthalmology and Visual Sciences from Research to Prevent Blindness. None.

Correlation of retinal layer measurements from optical coherence tomograms and 199832, (SX in fall of 2017), or layerestingd atrophy non ulcerative keratitis and inflammation: a large somewhat organized arealight microscopic images in globes from 20 dogs with chronic glaucoma

S Osinchuk, B Bauer, M Leis, L Sandmeyer and B Grahn

Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada

Purpose: To describe the correlation of retinal layers measured using optical coherence tomography (OCT) with retinal layers measured from light microscopic images in 20 globes from dogs with chronic glaucoma. Methods: Globes enucleated from 20 dogs with chronic glaucoma were routinely fixed, sectioned, embedded, and stained. Half of the eye cup was imaged using OCT adjacent to the cut edge. Nerve fiber and inner plexiform (NFIPF), inner retina (IR) and outer retina (OR) were measured as a ratio of total retinal thickness (TRT) in both OCT images and light microscopic images. IR was measured from the inner limiting membrane to the outer edge of the inner nuclear layer. OR was measured from the outer edge of the inner nuclear layer to the outer edge of the photoreceptor layer. Results: There was no significant difference between OCT (mean: 0.35) and light microscopic (mean: 0.39) measurements for the NFIPL (P = 0.15). There was no significant difference between OCT (mean: 0.50) and light microscopic (mean: 0.55) measurements for the IR (P = 0.06). There was no significant difference between OCT (mean: 0.48) and light microscopic (mean: 0.44) measurements for the OR (P = 0.06). Conclusions: Measurements collected using OCT are comparable to measurements collected from light microscopic images in canine globes with chronic glaucoma. Measurements derived from OCT images of the retina may be reliable for prognosticating canine patients with glaucoma. None.

Assessment of inherited retinal diseases in dogs using spectral domain optical coherence tomography (SD‐OCT)

SA Park,¹ J Rhodes,² S Iwabe,² W Pan,³ Huang J,³ GS Ying³ and AM Komaromy^1,2

¹College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; ²School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA; ³School of Medicine, University of Pennsylvania, Philadelphia, PA, USA

Purpose: To establish SD‐OCT assessment data in dogs with inherited retinal diseases including PDE6B‐rod‐cone dysplasia 1(RCD1), PRCD‐progressive rod‐cone degeneration (PRCD), CNGB3‐achromatopsia (ACHM), and RPE65‐Leber congenital amaurosis (LCA). Methods: High resolution SD‐OCT images (Spectralis, Heidelberg Engineering) of the retina OU were acquired in 5 planes: temporal (T); superotemporal (ST, including area centralis); superior (S); nasal (N); and inferior (I) in adult dogs with advanced disease: PDE6B‐RCD1 (n = 4 dogs, median age = 1.5 years); PRCD (n = 2, 4.3 years); RPE65‐LCA (n = 3, 5.2 years); CNGB3‐ACHM (n = 3, 4.2 years); and wild type (wt) dogs (n = 6, 5.5 years). Total, inner (from inner limiting membrane to inner plexiform layer‐inner nuclear layer interface), and outer (from inner plexiform layer‐inner nuclear layer interface to retinal pigment epithelium‐choroid interface) retinal thicknesses and ellipsoid zone were analyzed. Results: Compared to normal dogs the thickness of the outer retinal layers was significantly decreased (P < 0.01) in all imaging planes with RCD1, PRCD, and LCA but not ACHM. No significant thinning was observed in the inner retinal layer except in the N imaging plane of dogs with PRCD. Dogs with RCD1, PRCD, and LCA had significantly more disrupted ellipsoid zone in the presumed area centralis than normal dogs (P < 0.01). Conclusions: We successfully demonstrated the use of SD‐OCT to evaluate changes in the retinal morphology in dogs with inherited retinal dystrophies. We believe that SD‐OCT will provide valuable in vivo outcome measures in the development of novel therapeutics of retinal disease in dogs. The well preserved inner retina in the late stages of disease bauds well for some of the novel therapeutic modalities. Supported by NIH R01‐EY006855, R01‐EY019304, K12‐EY015398, P30‐EY001583. None.

Effect of withdrawing topical immune modulating treatment on schirmer tear test values in dogs with keratoconjunctivitis sicca

SA Park,¹ KL Good,² SM Thomasy,² PH Kass² and CJ Murphy^2,3

¹College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; ²School of Veterinary Medicine, University of California, Davis, Davis, CA, USA; ³School of Medicine, University of California, Davis, Davis, CA, USA

Purpose: To determine the effect of discontinuing topical immune modulation treatment on Schirmer tear test (STT) values over time in dogs with keratoconjunctivitis sicca (KCS). Methods: STT data of serial measurements from fourteen dogs (16 eyes) were analyzed. Inclusion criteria were dogs with (1) moderate to severe KCS (STT ≤10 mm/min with clinical signs of keratoconjunctivitis), or (2) KCS well managed with a topical immune modulating (IM) treatment including cyclosporine A and tacrolimus. Topical IM treatment was discontinued, but lubricant was continued and STT was monitored. The effect of age, gender, breed, clinical score, frequency and duration of treatment, baseline STT value and drug type on final STTs after IM withdrawal were evaluated with a mixed effects regression model. Data are expressed as mean ± SEM. P < 0.05 was considered statistically significant. Results: In 50% of the eyes (n = 8), STT values never decreased to 10 mm/min or less during the follow‐up period after discontinuation of IM treatment (136 ± 29 days). In the other 50% (n = 8), STT values decreased from 15.9 ± 4.7 mm/min to 6.1 ± 0.9 mm/min. In this group the time to decrease STT to less than 10 mm/min was 21.1 ± 9.5 days. Severe clinical signs of keratoconjunctivitis pre‐IM treatment and low baseline STT had significant effects on STT decrease after discontinuation of IM treatment (P < 0.05). Conclusions: The residual effect of IM treatment needs to be taken into consideration when clinical studies are designed based on dogs with previous IM for KCS treatment. Supported by the UC Davis Center for Equine Health, a generous gift from Dick and Carolyn Randall, and NEI grant P30EYT2576. None.

Ophthalmic findings in a captive population of panamanian golden frogs (Atelopus zeteki)

LN Pelych,¹ W Shellabarger,² E Noland³ and SE Aquino³

¹BluePearl Veterinary Partners, Southfield, MI, USA; ²Detroit Zoological Society, Royal Oak, MI, USA; ³Michigan State University College of Veterinary Medicine, East Lansing, MI, USA

Purpose: To describe the ocular morphology of, and to establish the parameters for select diagnostics in, Panamanian golden frogs (Atelopus zeteki). Methods: Twenty‐two frogs (10 males and 12 females) were subjected to slit lamps biomicroscopy, endodontic absorbent paper point tear testing (EAPPTT), rebound tonometry, rose bengal staining, palpebral fissure width measurement, blink rate measurement, corneal culture, and postmortem histology. Results: Atelopus zeteki have distinct brow ridges and mobile nictitans. Slit lamp biomicroscopy revealed avascular convex corneas with shallow anterior chambers. Iris colors ranged from yellow to green, with darkly pigmented peripheries. Pupils were round in both miosis and mydriasis. The mean blink rate was 0 within 10 min. The mean EAPPTT was 2 ± 1 mm in males, and 3 ± 1 mm in females. Mean male IOP was 21.6 ± 2.28 mmHg measured in a horizontal position, and 21.85 ± 2.7 mmHg measured in a vertical position. The mean female IOP was 17.45 ± 3.66 mmHg measured horizontally, and 17.5 ± 3.93 mmHg measured vertically. Enterococcus faecalis was cultured from the cornea of one frog. Conclusions: Tear production and blink rates were significantly low for both male and female frogs. Males had significantly smaller palpebral fissure widths, and increased IOP, when compared with females. None.

Orbital neoplasia in the dog: a retrospective analysis of 120 primary and secondary tumors in canine patients from 2005 to 2016

LR Proietto, RD Whitley, KA Marrazzo and CE Plummer

Department of Small Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, FL, USA

Purpose: To characterize primary and secondary neoplasms affecting the canine orbit in 120 canine patients from 2005 to 2016. Methods: Medical records were evaluated for age at diagnosis, presenting complaint, sex, breed, side affected, tumor classification as primary or secondary, histopathologic confirmation, mitoses and evidence of malignancy, clinical recurrence, therapies, and longevity of patients post‐diagnosis. Relationships between duration of disease, treatment, the potential for malignancy and metastatic disease were investigated. Data were statistically analyzed via student's t‐test, chi‐square analysis, and descriptive statistics where appropriate. Results: No significant breed or sex predilection was identified. Mean age at time of diagnosis was 9.77 ± 3.53 years. Fifteen presenting complaints were identified with a significant relationship between epistaxis and carcinoma (P < 0.01) and mass of the head with sarcoma (P < 0.01). Of the 120 tumors, 45 were primary and 75 were secondary. Twenty‐two histologic tumor types were identified (56.3% sarcomas and 28.6% carcinomas). The most common primary neoplasm was osteosarcoma (22.2%) and secondary neoplasm was adenocarcinoma (33.3%). Mitoses were not predictive of metastatic disease, recurrence or survival time. Metastatic disease did not correlate with a reduced longevity. Mean survival time was 279 ± 326 days. Life expectancy was extended from 162 ± 205 days to 352 ± 364 days if therapy was elected (P < 0.01). Both osteosarcoma and squamous cell carcinoma showed a significant favorable response to therapy (P < 0.05). Conclusions. The majority of orbital tumors were secondary through metastatic disease or orbital extension. Survival time post‐diagnosis was extended with therapeutic intervention but remained less than 365 days. Clinical metastatic disease and number of mitotic figures were not found to be significant in predicting survival time. None.

Effect of combination of EDTA and equine serum on in vitro anticollagenase and antigelatinase activity

RE Putnam and KM Smith‐Fleming

Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois

Purpose: To determine and compare the in vitro anticollagenase and antigelatinase activities of equine serum, EDTA solution, and equine serum‐EDTA combination solution over time. Methods: Fresh serum obtained from 5 healthy adult horses was added separately to EDTA‐containing blood collection tubes to create 5 individual 0.3% EDTA‐serum combination solutions. Serum samples were not pooled to allow investigation of inter‐individual variability. The in vitro anticollagenase and antigelatinase efficacy of combination solutions, plain equine serum samples and plain 0.3% EDTA solutions were measured by a commercial fluorescence assay and compared. All study solutions were stored at 4°C and the assays performed on days 0, 1, 2, 3, 5, and 7 of the storage period. Results: Plain EDTA solution showed superior collagenase and gelatinase inhibition at all time points compared to EDTA‐serum combination and serum alone. Combination solutions showed similar protease inhibition to serum alone. All solution types remained stable over the 7‐day storage period. High variability in protease inhibition existed between serum samples from different horses as well as between combination solutions. Conclusions: Combining equine serum and EDTA into a single solution shows no additional antiprotease activity compared to serum alone and is inferior to EDTA alone. Therefore, serum and EDTA should be used separately in clinical patients. Due to high variation in serum antiprotease activity between horses, use of multiple antiprotease agents in a single case may be prudent. 0.3% EDTA solution appears stable when stored at 4°C for 7 days. None.

Immunohistochemical mapping of corneal sensory innervation in mice: effects of Sjögren،s syndrome associated dry eye

RV Ramos,¹ RD Johnson,¹ RD Whitley,¹ DJ Gibson,² CQ Nguyen¹ and CE Plummer¹

¹College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; ²College of Medicine, University of Florida, Gainesville, FL, USA

Purpose: The purpose of the present study was to provide a detailed description of mouse corneal innervation involving immunohistochemically stained anterior‐cornea whole mounts in a rodent model of dry eye and compare to wild type rodent corneas. Methods: Six dry eye rodent model mice and fourteen wild type control mice were enucleated after euthanasia via CO2 inhalation in a closed chamber. All corneas were harvested with narrow corneoscleral rims and incisions were made to produce a cloverleaf‐shaped flat mount. The corneal sensory axons were labeled with immunofluorescence using primary antibodies against protein gene product (PGP) 9.5, substance P (SP), calcitonin gene‐related peptide (CGRP); and subjected to quantitative and qualitative analyses using a confocal microscope. Results: The main stromal nerve bundles entered the cornea at the limbus. Each stromal bundle gave rise through repetitive branching to a mildly dense midstromal plexus and dense subepithelial plexus. Sub‐basal density and anatomical complexity varied considerably among corneas and was less dense in the central cornea especially in dry eye syndrome corneas. Corneas from the dry eye rodent model have significantly decreased nerve fiber density of axons labeled for PGP 9.5 in the peripheral cornea compared to wild type. Similar findings were observed in the central cornea, however with no statistical difference was noted. Conclusion: This study provides comprehensive descriptions of the architecture of mouse corneal sensory innervation including the distribution of the two major neuropeptides, as well as, the innervation of the mouse cornea under desiccant conditions, such dry eye syndrome. None.

Effects of ophthalmic prednisolone and diclofenac on diabetes mellitus regulation in dogs

AJ Rankin,¹ KS KuKanich,¹ T Schermerhorn,¹ NM Bello,² JAS Huey,³ KE Fentiman¹ and JM Meekins¹

¹Kansas State University, Department of Clinical Sciences, Manhattan, KS, USA; ²Kansas State University, Department of Statistics, Manhattan, KS, USA; ³Memphis Veterinary Specialists, Cordova, TN, USA

Purpose: To evaluate and compare the effects of prednisolone acetate 1% (Pred Forte^®, Allergan, Irvine, CA) and diclofenac sodium 0.1% (Voltaren^®, Akorn, Lake Forest, IL) on diabetes regulation in dogs. Methods: Twenty‐two dogs diagnosed with diabetes mellitus and cataracts were enrolled. On days 0 and 32 after enrollment, serum fructosamine concentration, clinical scoring and body weight were performed. Dogs were administered either prednisolone (n = 10) or diclofenac (n = 12) topically in both eyes 4 times daily by the owner for 28 days. Data analysis was conducted using general linear mixed models. Results: There was no evidence for differences in fructosamine concentrations between the diclofenac and prednisolone treatment groups at day 0 (P = 0.9043) or day 32 (P = 0.3791). On day 0, clinical score was positively associated with serum fructosamine concentrations (P < 0.0001), whereby each 1 unit score increase was associated with approximately 45.6 ± 9.4 μmol/l increase in fructosamine. Serum fructosamine concentrations differed between genders (P = 0.0389) and was greater in spayed females than in castrated males by approximately 80.4 ± 30.1 μmol/l (P = 0.047). There was no evidence for an effect of treatment on clinical scores (P > 0.3109) or body weight (P > 0.1011). Conclusions: There was no evidence for any differential effect of ophthalmic prednisolone relative to diclofenac administered in both eyes 4 times daily for 4 weeks on diabetic regulation in dogs, as assessed by fructosamine concentrations, clinical scores, and body weight. Funded by Morris Animal Foundation Grant, KSU CVM Veterinary Medicine Mark Derrick Canine Research and Mentored Clinical, Applied, or Translational Research Grant. None.

Lymphocyte clonality testing on embedded tissue to diagnose intraocular lymphoma in a topically‐treated, subalbinotic, feline eye

CM Reilly,¹ M Henriksen,² KL Harmon³ and PF Moore³

¹Insight Veterinary Specialty Pathology, Austin, TX, USA; ²School of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA; ³School of Veterinary Medicine, University of California, Davis, Davis, CA, USA

Purpose: To describe the utility of PCR for Antigen Receptor Rearrangements (PARR) testing in the diagnosis of ocular lymphoma following topical treatment and partial response to therapy. Methods: A 9‐year‐old, male neutered, Siamese cat presented to UMN's ophthalmology service. An ophthalmic exam and testing for etiologic agents were performed. The eye was eventually enucleated. Histopathology, histochemistry, immunohistochemistry (IHC), and PARR testing were performed. Results: The presenting complaint was “change in eye color” OD. Anterior uveitis was diagnosed at initial exam, and 1% prednisolone acetate was prescribed. Systemic testing for known causes of feline uveitis was negative. During treatment, presumed herpes‐viral keratitis prompted a course of systemic famciclovir and topical ciprofloxacin, then switching to topical diclofenac. Blindness developed despite improving anterior uveitis, prompting enucleation. Histopathologically, the anterior uvea was minimally inflamed, with moderate lymphocyte infiltrates in the choroid and retina. The uvea was subalbinotic. Histochemistry for microorganisms was negative. IHC for CD3 labeled rare atypical cells. PARR testing for T‐cell receptor gamma revealed a clonal T‐cell expansion in a polyclonal (inflammatory) background, indicating T‐cell lymphoma and uveitis. The owners declined staging and oncology referral. Conclusions: This case highlights potential diagnostic challenges in ocular lymphoma, and the utility of IHC and PARR. Some index of suspicion on H&E slides is necessary, and uveal hypopigmentation may impact this assessment. IHC was able to identify the atypical cells’ phenotype, and PARR identified a clonal expansion, despite an inflammatory background and prior anti‐inflammatory treatment. Implications for further staging and treatment are significant. None.

Transscleral intracapsular lens extraction in dogs

MS Pedro, FTLB Roncatti, V Voget, ES Mello, CL Brunato and AL Teixeira

Department of Ophthalmology and Visual Sciences – Provet, Sao Paulo, Brazil

Purpose: In dogs, Zonular rupture can lead to lens subluxation, complete luxation and glaucoma. Intracapsular lens extraction (ICLE) for anterior lens luxation with the “open sky” approach can lead to corneal endothelial damage and scarring. The purpose of this study was to demonstrate a novel transscleral surgical approach to anterior lens luxation wich can minimize corneal damage and obtain good corneal transparency. Methods: 6 eyes from 5 dogs presenting with anterior lens luxation and acute glaucoma were operated using a transscleral surgical approach. A dorsal 180° scleral incision 3–4 mm posterior to the limbus was created. After tunneling toward Descemet's membrane, access to the anterior chamber was made with a #11 blade and corneal scissors. The anteriorly luxated lens was delivered with a Snellen's loop. A limited anterior vitrectomy was performed, and the sclera was closed in a simple interrupted pattern. Results: The average mean time of follow‐up was 6 months (range of 4–12 months). 5 of 6 eyes were visual before surgery and remained visual after surgery. All eyes remained normotensive in the post‐operative period. Glaucoma was not observed in any case. Minimal corneal scarring was noted in 2 eyes. Conclusions: This study demonstrated that the transscleral technique is a viable option for removal of an anteriorly luxated lens with minimal complications.

Keywords: Lens, anterior luxation, transscleral.

Outcome of anterior chamber shunt procedure in 104 eyes of dogs

A Saito, Y Kazama, H Iwashita and S Wakaiki

Triangle Animal Eye Clinic

Purpose: To evaluate the outcome of anterior chamber shunt (ACS) placement to treat canine glaucoma. Methods: Medical records of dogs receiving ACS (Ahmed Glaucoma Valve VFP7 or VFP8, New World Medical, Cucamonga, CA) between January 2010 and December 2015 were reviewed for duration of post‐surgical vision preservation by Kaplan‐Meier method. The outcome was compared based on a prior history of cataract surgery and breed by log‐rank test (significance P < 0.05). Ophthalmic drops were used as necessary to control intraocular pressure. Results: The study included 104 eyes of 97 dogs: 42 eyes (39 Shiba Inu), 20 eyes (18 American Cocker Spaniel (AMC)) and 42 eyes (40 other breeds), (38 eyes/34 males and 66 eyes/63 females), with a mean age of 7.8 years (range 0.5–13.3). The mean duration of postsurgical vision preservation was 52.2 months for all cases, 48.6 months with prior cataract surgery (33 eyes/30 dogs) and 47.5 months (54 eyes/51 dogs) without prior cataract surgery (P > 0.05 with vs. without cataract surgery). By breed, Shiba Inu maintained vision for 57.8 months, AMC for 31.9 months, and other breeds for 48.3 months with a significant difference between Shiba Inu and AMC. Vision was maintained in 80/87 eyes at 1 year, 41/55 at 2 years, 17/33 at 3 years, 12/21 at 4 years and 4/12 at 5 years post‐surgery. Conclusions: The visual outcome after ACS placement for the treatment of canine glaucoma was favorable compared to that of previous reports, particularly in Shiba Inu. None.

Clinical and histologic findings of 10 cats with congenital glaucoma

EM Salpeter, BS Bauer, SC Osinchuk, ML Leis, LS Sandmeyer and BH Grahn

Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada

Purpose: Report feline congenital glaucoma in 10 cats. Methods: This retrospective study evaluated clinical and histologic records of cats diagnosed with congenital glaucoma. Hematoxylin and eosin, periodic acid‐Schiff, immunohistochemical labels for smooth muscle actin, and cytokeratin were utilized. Lens surface area of fixed globes was calculated using Image‐Pro premier software. Morphologic changes were compared to a positive control group of 6 feline globes with secondary glaucoma. Results: Cat breeds affected with congenital glaucoma included domestic shorthairs and longhairs, and a Siamese cross. Average age at enucleation was 25 months in cats with congenital glaucoma and 12 years in cats with secondary glaucoma. Buphthalmos and corneal scarring were significant clinical findings in cats with congenital glaucoma and precluded intraocular biomicroscopic and indirect ophthalmoscopic examinations. Significant histologic findings of congenital glaucoma included uveal hypoplasia, recessed or hypoplastic filtration angles, microphakia, elongated ciliary processes, and mild glaucomatous retinal degeneration. Only the latter finding was similar in those with secondary glaucoma. Statistically significant differences were detected in lens surface area between cats with congenital glaucoma and those with secondary glaucoma (P = 0.01). Conclusions: Congenital glaucoma manifests most commonly in cats less than 2 years of age with buphthalmos, corneal scarring, microphakia, uveal hypoplasia, recessed or hypoplastic filtration angles, and elongated ciliary processes. Supported by the Companion Animal Health Fund. None.

Short term findings in 25 dogs treated with micropulse transscleral diode cyclophotocoagulation for refractory glaucoma

JS Sapienza, K Kim and E Rodriguez

Long Island Veterinary Specialists, Plainview, NY, USA

Purpose: Transscleral diode laser cyclophotocoagulation is an established method for treatment of refractory glaucoma in dogs, but is associated with significant postoperative ocular complications. The purpose of this study is to report the findings of a novel use of micropulse transscleral diode laser cyclophotocoagulation (MP‐TSCP) in glaucomatous dogs. Methods: Retrospective study of 25 dogs (32 eyes) treated with MP‐TSCP with a minimum of 2 months of follow‐up. Reported outcomes were intraocular pressure (IOP), treatment parameters, reduction in medications, complications and incidence of repeat therapy. Results: 25 dogs (32 eyes) were evaluated. The mean age was 8.5 years. Mean preoperative IOP was 33.6 mmHg, and postoperative IOP was 19.4 mmHg. First treatment success rate was 17/32 eyes (53.1%). Repeat laser was performed in 12 eyes with 9/12 eyes responding favorably for a total IOP control of 26/32 eyes (81.2%). Mean energy levels employed was 133.9 S and 2308 mV at 31.3% duty cycle. Reduction of medications was from a mean of 3.6 medications preoperatively to 2.9 medications postoperatively. Complications included corneal ulcers (n = 5) and repeat treatment in 12 eyes. Conclusions: MP‐TSCP was successful in controlling the IOP and in reducing postoperative medications with minimal inflammation and complications. The procedure can be repeated. Future investigations to study effective treatment parameters are warranted in a larger series of patients over a longer period of evaluation. None.

Micropulse transscleral cyclophotocoagulation in dogs with glaucoma: preliminary results

L Sebbag, RA Allbaugh, T Strong, RA Strauss, RF Wehrman and G Ben‐Shlomo

Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA

Purpose: To describe the procedure, efficacy and complications of micropulse transscleral cyclophotocoagulation (mTSCPC) in dogs with glaucoma. Methods: Fourteen dogs affected with either primary (n = 9) or secondary (n = 5) glaucoma were treated with mTSCPC. The procedure was performed under heavy sedation (n = 10) or general anesthesia (n = 4). Laser power varied from 2000–2800 mW. The probe was moved in a continuous sliding motion to treat each hemisphere for 90–180 s. Complete ophthalmic examination, intra‐ocular pressure (IOP) and central corneal sensitivity were evaluated over time. Glaucoma was deemed controlled if IOP < 20 mmHg. Results: Dogs initially treated with low power (3/14, 2000 mW) required a repeated procedure within 23–35 days. Post‐operative ocular hypertension occurred in 6/14 dogs. Post‐operative uveitis was non‐existent or mild (trace to 1+ flare). At last recheck (range 7–181, average 101 ± 60 days), 7/14 dogs had controlled glaucoma with a mean IOP = 14 mmHg, representing 50–87% IOP reduction compared to baseline. The remaining seven dogs were uncontrolled and 6/7 underwent end‐stage procedure (chemical ablation of ciliary body, enucleation). Success was greater in cases of primary glaucoma. Complications included mild and transient uveitis (n = 8), corneal hypoesthesia (n = 4), neurotrophic corneal ulceration (n = 5, only seen in brachycephalic dogs) and conjunctival burn (n = 1). Conclusions: Preliminary findings suggest that mTSCPC can be performed under sedation, requires high power (≥2500 mW) in dogs, causes minimal to no inflammation, and results in a better outcome when the etiology of glaucoma is primary. Further studies could evaluate the benefit of repeating the procedure periodically or combining mTSCPC with a gonio‐implant. None.

Tear fluid collection in dogs and cats using ophthalmic sponges

L Sebbag,¹ DM Harrington² and JP Mochel³

¹Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA; ²Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, USA; ³Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA

Purpose: To describe a rapid and non‐invasive method for tear fluid collection in dogs and cats. Methods: Ten healthy dogs and 10 healthy cats were included. A strip (4 × 10 mm) of either cellulose or polyvinyl acetal (PVA) sponge was inserted into the ventral fornix of each eye for either 15, 30 or 60 s. The wetted strip was placed into a 0.2‐ml tube that was first punctured at its bottom. Tears were eluted through the drainage hole into a 1.5‐ml tube via centrifugation. Tear volume absorbed (VA) and tear volume recovered (VR) were calculated as the difference of the post‐ and pre‐ collection weight of the 0.2‐ml tube and 1.5‐ml tube, respectively. Recovery ratio (RR) was determined as the ratio between VR and VA. Results: Ophthalmic sponges were well tolerated by all subjects. In dogs and cats, median (95% range) VA, VR and RR were: 44 μl (11–106 μl) and 16 μl (2–43 μl); 27 μl (1–84 μl) and 6 μl (0–29 μl); 64% (7–91%) and 35% (0–86%), respectively. PVA sponges achieved significantly greater VR in cats and RR in both species. All parameters were significantly greater with a collection time of 60 vs. 30 and 15 s. Body weight was associated with VA, VR, RR in dogs but not cats. Conclusions: PVA is better than cellulose for tear collection given its superior recovery. Ophthalmic sponges could facilitate routine analysis of tear fluid in dogs and cats, although further studies are needed to evaluate the quality of tears obtained with this method. None.

Long‐term phacoemulsification outcome in raptors – a retrospective study (1999–2014)

AB Sigmund, DVH Hendrix, MP Jones and DA Ward

College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA

Purpose: To determine outcome of phacoemulsification in raptors at the University of Tennessee Veterinary Medical Center. Methods: Medical records from seven (11 eyes) non‐releasable raptors were reviewed. Four underwent bilateral phacoemulsification while three had unilateral surgery. Due to a low sample size, statistics were not done. Results: Six raptors (9 eyes) including three bald eagles (Haliaeetus leucocephalus), two red‐tailed hawks (Buteo jamaicensis), and one peregrine falcon (Falco peregrinus) had long‐term follow up. Another bald eagle was euthanized two months after surgery due to post‐operative complications. Two of eleven eyes (18%) had intraocular lens (IOL) placement with both eyes developing complications; one with intermittent anterior uveitis that developed a complete pupillary membrane and the other with refractory pseudophakic glaucoma resulting in euthanasia (the opposite aphakic eye in this eagle was visual at the time of euthanasia). Seven of nine eyes (78%) from six raptors had long‐term follow up (median 59 months, range 27 to 105 months) and were visual. None of these eyes developed increased intraocular pressures during the follow up period. Two eyes (22%) developed intermittent anterior uveitis managed with periodic prednisolone acetate. One that was pseudophakic was blinded by a pupillary membrane. One aphakic eye developed a rhegmatogenous retinal detachment. Conclusions: Probability of return to vision after phacoemulsification in raptors appears good as 7/9 eyes (78%) remained visual after 27 months post‐phacoemulsification. The two eyes that received intraocular lenses became blind. None.

Immunophenotyping of canine corneal endothelium and preiridal cellular membranes

DG Sledge, L Huang and M Kiupel

Veterinary Diagnostic Laboratory, Michigan State University, Lansing, MI, USA

Purpose: Canine preiridal membranes are of pathologic significance as they are often associated with peripheral anterior synechia and secondary glaucoma. While preiridal fibrovascular membranes are associated with intraocular production of vascular growth factors, the histogenesis and cause of preiridal cellular membranes are less clear. Preiridal cellular membranes resemble corneal endothelium, being composed of a single layer of attenuated to rectangular in profile cells that have variably distinct cell borders, small amounts of lightly basophilic vesiculated cytoplasm, and oval nuclei. Given the morphologic similarity between corneal endothelium and preiridal cellular membranes, the goals of the current study were to immunophenotype normal canine corneal endothelium and to compare immunophenotypic patterns of normal corneal endothelium to that of preiridal cellular membranes. Method: Based on previous immunophenotyping studies done on human corneal endothelium, immunohistochemistry for neuron specific enolase (NSE), S‐100 protein, vimentin, and Tamm‐Horsfall glycoprotein (THGP) was performed on 5 normal canine eyes and 5 canine eyes with previously diagnosed preiridal cellular membranes. Results: Corneal endothelium in normal canine eyes had strong intracytoplasmic immunoreactivity for NSE, S‐100, and vimentin, and weak intracytoplasmic immunoreactivity for anti‐THGP antibody. Preiridal cellular membranes had a similar pattern of immunoreactivity for all evaluated markers. In a number of cases, there was also a PAS‐positive basement membrane between basal segments of the preiridal cellular membranes and the anterior face of the iris. Conclusions: These results indicate that normal canine corneal endothelium is immunophenotypically similar to human corneal endothelium, and that preiridal cellular membranes are derived from corneal endothelium. Supported by an MSU CVM Endowed Companion Animal Fund grant. None.

Optic neuritis in dogs: 96 cases (1983–2016)

SM Smith, HD Westermeyer, CL Mariani, BC Gilger and MG Davidson

Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, USA

Purpose: To characterize ocular and neurologic findings, causes, and treatment outcomes of dogs with optic neuritis. Methods: Medical records from dogs with a diagnosis of optic neuritis at North Carolina State University, College of Veterinary Medicine Veterinary Hospital between 1983 and 2016 were reviewed. Results: Ninety‐six cases (20 unilateral, 76 bilateral), comprised of 38 males and 58 females with a mean age of 6.1 ± 3.0 years (range 0.5–13) were identified. Seventy‐four cases were presented for vision loss, and 34 were presented for other neurologic abnormalities. Funduscopic findings included optic nerve head elevation (n = 92), peripapillary retinal edema or separation (n = 37), retinal hemorrhage or dilation of retinal vasculature (n = 23), and multiple inflammatory foci in the peripapillary region (n = 13). Retrobulbar optic neuritis was diagnosed in 4 cases. The final diagnoses included: multifocal meningoencephalitis of unknown etiology (MUE, n = 35), isolated optic neuritis (I‐ON, n = 42), neoplasia (n = 10), microbial infection (n = 6), orbital inflammation (n = 2), and suspected ivermectin toxicity (n = 1). Dogs with I‐ON were more commonly male, and medium to large breed, when compared to dogs with MUE. Follow‐up was available in 72 cases, 50 of which remained blind, 10 had partial visual improvement, and 12 were assessed as having normal vision in affected eye(s). Conclusions: Optic neuritis was most commonly associated with multifocal MUE or was isolated as the sole neurologic finding, with a similar distribution between the two groups. Findings suggest that a clinical syndrome of isolated optic neuritis, distinct from multifocal MUE, occurs in dogs. None.

Evaluation of a reliable outer retinal margin marker and the discernability of outer retinal bands on OCT images of common laboratory animal species

P Soukup,^1,2 P Maloca,^3,4 B Altmann,² EA Atzpodien² and SA Pot¹

¹Equine Department, Section of Ophthalmology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland; ²Roche Innovation Center Basel, Basel, Switzerland; ³OCTlab Research Laboratory, Department of Ophthalmology, University of Basel, Basel, Switzerland; ⁴Moorfields Eye Hospital, London, UK

Purpose: To identify a clear marker for the RPE/Bruch's membrane complex as outer retinal margin (ORM) and to quantify the discernability of outer retinal bands (ORB) on Optical Coherence Tomography (OCT) images from different species and anatomic locations. Methods: Spectralis HRA+OCT (Heidelberg Engineering) images were acquired from locations dorsal, central and ventral to the optic disc in healthy, anesthetized animals. Only best quality OCT B‐scans as defined by the instrument quality score were used. The presence and discernability of a common ORM marker was evaluated and quantified. B‐scans demonstrating the highest discernability of individual ORB were defined as “ideal presentation”. The percentage of “ideal presentation” B‐scans per total number of B‐scans was calculated. OCT‐histopathology comparison was used to further confirm the ORM marker. Results: Five‐hundred and ten B‐scans from ninety subjects were evaluated (minipig: 120/18, rabbit: 49/9, rat: 160/28, mouse: 157/27, human: 12/4, primate: 12/4). The choriocapillaris was the most reliable ORM marker across species, identified in 100% of minipig, 73% of rabbit, 79% of rat, 53% of mouse and 100% of human and primate OCT scans. The percentage of “ideal presentation” B‐scans was 13% in minipigs, 78% in rabbits and 78, 91, 29 and 62% in pigmented rats and mice and albino rats and mice, respectively. Conclusions: ORM marker discernability and ORB presentation likely vary due to differences in retinal anatomy and pigmentation between animal species and strains. These differences need to be taken into account for qualitative and quantitative OCT evaluation in comparative ophthalmology research. None.

Effects of oral raltegravir in cats with experimentally‐induced ocular and respiratory feline herpesvirus‐1 infection

CB Spertus,¹ MR Pennington,² GR Van de Walle,² ZI Badanes,¹ BE Judd,¹ HO Mohammed³ and EC Ledbetter¹

¹Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA; ²Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA; ³Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA

Purpose: To determine the effects of oral raltegravir (Isentress^®, Merck & Co., Kenilworth, New Jersey) treatment in cats with experimentally‐induced ocular feline herpesvirus‐1 (FHV‐1) infection. Methods: A randomized, masked, vehicle‐controlled, 30‐day trial was performed using 14 nonvaccinated specific‐pathogen‐free cats with experimental FHV‐1 infection induced by topical ocular inoculation. Cats received oral raltegravir (80mg) or vehicle (lactulose) capsules by mouth, twice daily, for 14 days. Cats were monitored after inoculation for 30 days. Ophthalmic examinations were performed every two days and ocular disease scores were calculated. Sneezing and nasal discharge were scored and respiratory rates were assessed every two days. Ocular samples for FHV‐1 qPCR and virus isolation assays were collected every 3 days. Results: After inoculation, all cats developed ocular and respiratory disease typical of primary FHV‐1 infection, including conjunctivitis and corneal ulceration. Using regression analysis, the raltegravir treatment group had significantly lower ocular disease scores, respiratory disease scores, and respiratory rates over time compared to the vehicle treatment group. The median duration of ocular viral shedding was significantly shorter in the raltegravir group compared to the vehicle group. Although the raltegravir treatment group had lower ocular viral loads in comparison to the vehicle treatment group, the difference was not statistically significant. Hemogram and serum biochemistry panel values were unremarkable throughout the study. Conclusions: Oral raltegravir, administered twice daily, may be a viable treatment option to alleviate the ocular and respiratory clinical signs associated with FHV‐1 infection in cats. Supported by the Foundation for Ophthalmology Research and Education International. None.

Biofilm formation in ocular bacterial isolates

J Stiles,¹ MN Seleem,² A Hassan,² W Younis² and GK Hammac²

¹Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA; ²Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University West Lafayette, IN, USA

Purpose: To evaluate bacterial isolates from diseased ocular surfaces of dogs and horses for biofilm formation. Methods: Standard methods were used to identify bacterial isolates. Biofilm formation was evaluated using two different methods: Congo red agar (CRA) and microtiter plate assay followed by crystal violet staining. Various antibiotics alone and in combination, as well as other compounds such as EDTA, were evaluated for ability to disrupt biofilm. Results: Eighteen isolates were from dogs and 6 from horses. Thirteen isolates were from conjunctiva and 11 from cornea. Isolate genera included Streptococcus (12), Staphylococcus (8), Pseudomonas (1), Bacillus (1), Enterobacter (1) and Escherichia (1). Twenty three of 24 (96%) isolates formed biofilm with 6 (26%) forming a strong film, 9 (39%) a moderate film, and 8 (35%) a weak film. Microtiter plate assay was more sensitive in detecting biofilm formation than CRA. Conclusions: A large majority of bacteria from diseased eyes formed biofilm, which may explain why some infections are difficult to resolve. Standard culture and sensitivity methods cannot detect the ability of bacteria to form biofilm. None.

Corneal sensitivity and relationship between corneal biometric parameters in glaucomatous and normal cats

MR Telle,¹ N Chen,² JA Kiland,² D Shinsako^1,2 and GJ McLellan^1,2

¹Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin – Madison, Madison, WI, USA; ²Department of Ophthalmology & Visual Sciences, University of Wisconsin – Madison, Madison, WI, USA

Purpose: To determine the effect of feline congenital glaucoma (FCG) on corneal sensitivity and its relationship to corneal biometric parameters, including central corneal thickness (CCT) and corneal diameter (CD). Methods: Corneal sensitivity (estimated by corneal touch threshold (CTT) using Cochet‐Bonnet esthesiometry), CCT using ultrasonic pachymetry, intraocular pressure using rebound tonometry, and maximal horizontal CD were measured in 20 FCG cats and 20 normal cats, in both males and females aged 7 months – 3.5 years old. All procedures were conducted under an Institutional Animal Care and Use Committee‐approved protocol. Data from eyes with documented confounding ocular abnormalities were excluded from the study. Data were analyzed by linear regression, paired student t‐test for between eye comparisons, and unpaired student t‐test for comparisons between groups. Relationships between parameters were evaluated by Pearson or Spearman correlation coefficients. For all statistical tests, P values < 0.05 (adjusted for multiple comparisons) were significant. Results: Mean CTT and CCT values were lower in glaucomatous eyes relative to normal eyes but differences were not statistically significant. Mean CD was significantly larger in glaucomatous eyes relative to normal eyes (P = 0.0008 OD and P < 0.0001 OS). A significant negative correlation was present between CD and CTT in glaucomatous eyes (P < 0.0005, r = −0.85 OD; P = 0.0409, r = −0.57 OS). Conclusions: Glaucomatous eyes have significantly larger CDs when compared with normal eyes, and larger CDs correlated with decreased corneal sensitivity in this group. Further studies are warranted to explore the effect of buphthalmos and corneal enlargement on corneal sensitivity and innervation in FCG. Supported by Research to Prevent Blindness; NIH grant P30 EY016665; Lions Eye Bank of Wisconsin. None.

Evaluation of anti‐angiogenic properties of equine amniotic membrane homogenate in tears of dogs with vascularized ulcerative keratitis

T Villar,¹ AL Pascoli^2,3 and BC Martins¹

¹Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana‐Champaign, IL, USA; ²College of Veterinary Medicine, São Paulo State University, Jaboticabal, SP, Brazil; ³College of Veterinary Medicine, Regional University of Blumenau, Blumenau, SC, Brazil

Purpose: To evaluate the anti‐angiogenic property of equine amniotic membrane homogenate (EAMH) and its in‐vitro effect in tears of dogs with vascularized ulcerative keratitis. Methods: Equine pigmented epithelium derived factor (PEDF) and vascular endothelial growth factor (VEGF) were evaluated by enzyme immunoassays (ELISA) in EAMH from ten mares. Tear samples (n = 40) from affected and contralateral eyes of dogs with vascularized corneal ulcers were used. Tears from 25 healthy dogs were used as control. Tear samples from affected eyes were pooled as follows: untreated tears (G1), tears with buffer (G2), tears with 0.21 mg/ml EAMH (G3), tears with 0.42 mg/ml EAMH (G4). Contralateral tears (G5) and normal tears (G6) were also analyzed. Samples were submitted to ELISA and Western Blot (WB) for evaluation of canine VEGF. Results: Mean concentration of equine PEDF and VEGF in EAMHs were 72.34 ± 7.07 ng/ml and 0.658 ± 0.07 ng/ml, respectively. Concentrations of canine VEGF were elevated in affected and contralateral tears, compared to control group. Concentration of VEGF were decreased in samples treated with high dose of EAMH (G4) compared to those treated with buffer (G2). Conclusions: EAMHs maintained a high concentration of PEDF after processing. VEGF concentrations are elevated by 11‐fold in tears of dogs with vascularized ulcerative keratitis. High dose of EAMH was able to decrease the VEGF concentration in tears of dogs with vascularized corneal ulcers. Results suggest that EAMH may be able to reduce VEGF concentration in‐vitro. Supported by Wayne D. and Josephine H. Spangler Endowment Fund – Companion Animal Research Grant Program. None.

Evaluation of cell death markers during corneal wound healing in the horse

RF Wehrman,¹ A Charli,² AG Kanthasamy² and G Ben‐Shlomo¹

¹Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA; ²Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA

Purpose: Corneal wound healing is a complex process whose mechanisms are not completely understood. The aim of this study was to evaluate markers of cell death in the equine cornea, following wounding. Methods: Fourteen equine corneas from horses euthanized for reasons unrelated to this study were randomly assigned to one of two groups: wounded (n = 8) or unwounded (n = 6) controls. The axial cornea was wounded by applying a 6 mm filter paper disk soaked in 1N‐NaOH for 60 s. Corneas were subsequently cultured using an air‐liquid interface model. A rocker was set at a 6‐degree incline and corneas bathed with media 8 times per minute to simulate blinking. Corneal ulcers were measured daily and culture media collected at time 24, 48, and 72 h after wounding, and frozen at −20°C. Media were evaluated employing a lactate dehydrogenase (LDH) colometric assay, and caspase‐3 enzymatic assay to assess cell death and apoptosis, respectively. Results: All corneal ulcers healed within 72 h. Average (±SD) LDH absorbance units (AU) for wounded corneas were 0.61 ± 0.05, 0.4 ± 0.02, and 0 AU for T24, T48 and T72, respectively, and for unwounded corneas 0.58 ± 0.07, 0, and 0 AU for T24, T48 and T72, respectively. No caspase‐3 activity was detected in media from either wounded or unwounded corneas at any time point. Conclusions: Cell death in ex vivo, alkaline‐burned, equine corneas is not associated with caspase‐3 mediated apoptosis. To our knowledge, this is the first study evaluating the expression of cell death markers during ex vivo equine corneal wound healing. This study was partially supported by Iowa State Veterinary Clinical Sciences Research Incentive Grant and the American Quarter Horse Foundation. None.

Safety of topically applied 0.5% and 1% pirfenidone in a model of canine subconjunctival fibrosis

HD Westermeyer, JH Salmon, A Oh and FM Mowat

Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Purpose: To evaluate the safety and tolerability of topically applied 0.5% and 1% pirfenidone in dogs. Methods: A subconjunctival silicone implant (5 mm diameter × 1 mm thickness) was surgically implanted in the dorsal lateral quadrant, 5 mm posterior to the limbus in 12 purpose bred beagles. Following implant placement, 0.5% pirfenidone (Abcam, Cambridge, MA) in artificial tears (Refresh Plus; Allergan, Inc., Irvine, CA, USA) was applied four times a day to the eye of 9 randomly selected dogs, while the remaining 3 dogs received artificial tears only for 4 weeks. After a two week washout, the same procedure was performed in the opposite eye, but 1% pirfenidone was applied. Ocular surface and anterior segment irritation and inflammation scores and intraocular pressure were recorded weekly. Full field electroretingrams were performed after three weeks of 1% pirfenidone administration. Results: There was no difference in intraocular pressure between treated dogs and controls. There was no difference in ocular irritation scores between treated dogs and control dogs. Blepharospasm for 1–2 min was noted immediately after drug application using 1% pirfenidone during the first week of treatment. Implants in two dogs, one in the 0.5% and one in the 1% pirfenidone treatment group, extruded. No other adverse effects were noted. Conclusion: Topical ophthalmic application of 0.5% and 1% pirfenidone appears to be well tolerated and safe in dogs. Supported by a NCSU CVM Intramural Research Grant. None.

Use of 0.03% aqueous tacrolimus for suspected immune‐mediated ocular surface inflammation in cats

AM Willis

VCA City Cats Hospital, Arlington, MA, USA

Purpose: To describe the use, tolerability and efficacy of compounded aqueous ophthalmic 0.03% tacrolimus suspension in cats in the steroid‐sparing management of corneal and conjunctival conditions suspected to have an immune‐mediated pathogenesis. Methods: Retrospective evaluation. Cats treated with tacrolimus for management of eosinophilic keratitis (EK; n = 10), idiopathic non‐ulcerative keratitis (INUK; n = 4), stromal keratitis (n = 5), eosinophilic conjunctivitis/blepharitis (EC/B; n = 7), follicular conjunctivitis (FC; n = 6), and proliferative conjunctivitis/keratitis associated with symblepharon (PK/CS; n = 7) were included. Pre‐treatment diagnostic methods included brush cytology of the cornea and/or conjunctiva (n = 28), corneal culture and sensitivity (C&S; n = 2), conjunctival biopsy (n = 3), and corneal or conjunctival multiplex PCR analysis (n = 5). Tacrolimus was initiated q 12 h for all patients, except for stromal keratitis patients, which were started at a q 24 h dosing initially, and gradually increased to q12 h dosing. Adjunctive antiviral and antibiotic therapy were used selectively. Results: Eosinophils, mast cells, or both were identified in either cytology preparations or histopathology of all cats diagnosed with EK or EC/B. Lymphoplasmacytic inflammation was the predominant characteristic in cytology of FC and PK/CS patients. Aerobic corneal C&S was negative in one patient and positive in one patient tested. Mutliplex PCR was negative for FHV‐1 in 5/5 cases tested, but positive for Mycoplasma felis in 3/5 patients. Aqueous‐based tacrolimus was well tolerated by all cats. Remission of active disease was achieved in 8/10 cats with EK, ¾ cats with INUK, 5/5 cats with SK, 3/7 cats with EC/B, 4/5 cats with FC and 7/7 cats with PK/CS. Corneal ulceration associated with EK and PK/CS healed without complication with tacrolimus treatment and supportive antibiotic and antiviral therapy. Miosis was a consistent side effect of tacrolimus treatment, suggesting intraocular or systemic absorption. No negative topical or systemic effects of treatment were noted. Conclusions: Tacrolimus in an aqueous 0.03% concentration is a well‐tolerated and effective steroid alternative for principle and adjunctive treatment of EK, INUK, FC, PK/CS and SK in cats. Tacrolimus was less responsive as a sole topical anti‐inflammatory therapy for cats with EC/B in patients with atopy. Miosis is a consistent side effect of topical treatment, regardless of compounding source or preservative. None.

Anterior segment parameters in normal dogs using the Pentacam‐HR^® Scheimpflug system

AE Wolfel,¹ SL Pederson,¹ AM Cleymaet,¹ A Hess² and KS Freeman¹

¹College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA; ²Department of Statistics, Colorado State University, Fort Collins, CO, USA

Purpose: To describe and compare normative anterior segment parameters between different canine age groups using the Pentacam‐HR^® Scheimpflug system (Pentacam). Methods: Thirty‐six sedated canines (60 eyes) of varying ages and breeds were imaged with the Pentacam; only non‐diseased anterior segments were included. Dogs were divided into three age groups: young (1–5 years), middle‐aged (6–10 years), and old (11–15 years). Values assessed included central corneal thickness (CCT), anterior and posterior corneal elevation (ACE/PCE), anterior and posterior corneal curvature metrics, corneal volume (CV), anterior and posterior corneal astigmatism (AA/PA), anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA). Tukey adjusted pairwise comparisons were performed. Results: CCT overall (mean ± SD) was 631.07 ± 59.91 μm and by age was as follows: CCT1–5 was 608.60 ± 48.63 μm, CCT6–10 equaled 648.57 ± 51.06 μm, and CCT11–15 was 635.37 ± 73.71 μm. ACE was 9.08 ± 0.58 mm, PCE measured 8.04 ± 0.50 mm, and CV was 58.13 ± 5.39 mm³. Astigmatism values were 1.34 ± 0.94D for AA and 0.46 ± 0.44D for PA. Anterior chamber values were 3.76 ± 0.56 mm for ACD, 383.68 ± 66.24 mm³ for ACV, and 23.62 ± 29.33˚ for ACA. Significant differences were only found between young and middle age groups for CV with CV1–5 (55.08 ± 4.08 mm³) significantly less than CV6–10 (60.32 ± 4.19 mm³), (P = 0.02). Conclusions: Multiple canine anterior segment parameters were successfully measured with the Pentacam and some age differences were found. While central corneal thickness does increase from young to middle‐age dogs, this was not statistically significant with our sample size. Corneal volume significantly increased with age between young and middle‐aged dogs. Other anterior segment parameters do not consistently show variation between age groups of normal dogs. Funded by Young Investigator Grant Program, Center for Companion Animal Studies, Colorado State University. None.

Safety and efficacy of treatment with mycophenolate mofetil in dogs with sudden acquired retinal degeneration syndrome

WM Young, A Oh, J Williams, ML Foster and FM Mowat

Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Purpose: Sudden acquired retinal degeneration syndrome (SARDS) is a poorly understood cause of canine acute blindness for which there is no established therapy. As SARDS may be an immune‐mediated condition, some veterinary ophthalmologists advocate treatment with immunosuppressive corticosteroids. However, these may exacerbate some clinical signs associated with SARDS. The immunomodulatory medication mycophenolate mofetil was investigated in this study as an alternative therapy. Methods: Ten dogs with acute SARDS were treated with 10 mg/kg twice daily of oral mycophenolate mofetil for approximately 6 weeks. Before and after treatment, owners were surveyed and animals underwent blood and urine sampling, ophthalmic examination, electroretinography, testing of visual navigation ability, and optical coherence tomography. Results: Mild treatment side effects of gastrointestinal upset in 2 patients were ameliorated by 20% dose reduction and all patients completed the treatment course (mean of 45 days). No changes were detected in ophthalmic examination findings. Owners did not report any change in vision, and no significant blood or urine abnormalities occurred with treatment. Electroretinography did not show any measurable retinal responses before or after treatment. Visual navigation ability significantly declined in mesopic lighting conditions, and the outer nuclear layer thinned significantly despite treatment. Conclusions: Although well tolerated, mycophenolate mofetil had no measurable effect on vision, electroretinographic response, or retinal thickness in dogs with SARDS. Mycophenolate mofetil as a sole therapy is not effective in reversing retinal dysfunction and preventing degeneration associated with SARDS. ACVO Vision for Animals Foundation Resident Grant VAF2016‐03. None. Stokes Pharmacy, 607 S Main St, King, NC 27021.

Retrospective evaluation of canine palpebral masses treated with debulking and cryotherapy: 46 cases

AE Zibura,¹ MdL Henriksen,^1,2 C Lim^1,3 and CM Reilly⁴

¹Comparative Ophthalmology, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA; ²Comparative Ophthalmology, College of Veterinary Medicine, Colorado State University, Fort Collins, CO, USA; ³Eye Care for Animals, Chicago, Illinois 3. Insight Veterinary Specialty Pathology, Austin, TX, USA

Purpose: To evaluate the frequency of recurrence of canine palpebral masses treated with a debulking and cryotherapy method. Methods: Medical records of dogs that underwent debulking and cryotherapy for palpebral masses from December 2010 to November 2015 at the University of Minnesota's Veterinary Medical Center were reviewed. All masses included in the study were submitted for histopathology at either Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) or UC Davis’ pathology department. A telephone survey with owners was used to determine recurrence and duration to recurrence. Results: Forty‐six palpebral masses (31 dogs) were included in this retrospective study. Palpebral masses included in this study were: adenomas 17/46 masses (37%), epitheliomas 8/46 (17.4%), melanocytoma 1/46 (2.2%), papillomas 6/46 (13%), inflammatory masses 6/46 (13%), mixed neoplasms containing both adenomas and papillomas 6/46 (13%), and mixed neoplasms containing both epitheliomas and papillomas 2/46 (4.4%). Of the 7 masses that were noted to recur (7/46, 15.2%), 2 were epitheliomas (2/8, 25%), 1 was a melanocytoma (1/1, 100%), 1 was a papilloma (1/6, 16.7%), and 3 were mixed masses containing both an adenoma and a papilloma (3/6, 50%). The average time to recurrence of these 7 masses was 367.9 days [range: 30–904 days]. Conclusions: Debulking and cryotherapy is an effective method of treatment for eyelid masses in dogs with a study recurrence rate of 15.2%. Results also suggest that melanocytomas may have the highest recurrence rate (100%), followed by mixed adenoma‐papilloma masses (50%), and epitheliomas (25%), although more extensive research is necessary. None.

Surgical treatment for enucleation of a canine eye that has previously undergone a parotid duct transposition

JL Zimmer, KA Diehl and KE Myrna

Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA

Purpose: To identify techniques for enucleation following parotid duct transposition (PDT) surgery in clinical practice as well as to characterize demographics and outcomes associated with the procedure. Methods: An online poll of ACVO members and residents was performed to investigate the breed, reason for enucleation, time between PDT and enucleation, surgical technique employed, complications observed and additional therapy instituted. Results: Thirteen dogs fit the inclusion criteria. Small breed dogs (<15 kg) made up 77% of patients. The time between PDT and enucleation was <6 months (2/13), 6–12 months (4/13) and ≥1 year (7/13). Reasons for enucleation included: advancing corneal disease (6/13), discomfort (5/13), reaction to saliva (2/13), decreased saliva production (1/13) and glaucoma (1/13). Surgical techniques included: no surgical manipulation of the duct for 2/13, ligation of the parotid duct for 7/13 and re‐routing the duct to the oral cavity for 4/13. One patient who underwent duct ligation experienced prolonged dilation of the parotid duct that resolved without additional therapy. No other complications were reported. Conclusions: Ligation or re‐routing of the parotid duct to the oral cavity are appropriate adjunctive surgical techniques for enucleation following PDT. Two patients with a non‐functional PDT had complication‐free enucleation with no manipulation of the duct at the time of surgery. Prolonged dilation of the duct is possible after enucleation and may resolve with time. None.

Evaluation of transconjunctival thermal electrocautery for treatment of canine distichiasis: 88 eyelids (2013–2016)

KL Zimmerman and SL Reinstein

Veterinary Specialty and Emergency Center, BluePearl Veterinary Partners, Levittown, PA, USA

Purpose: To describe a successful, simple, and widely available treatment for canine distichiasis. Procedure: Retrospective analysis of medical records for canine patients who underwent transconjunctival thermal electrocautery treatment (TCEC) for distichiasis alone or with concurrent eyelid surgery between 2013 and 2016 at BluePearl Pennsylvania. Results: Twenty‐six dogs (n = 88 eyelids) were included in the study. Sixty eyelids (68%) were treated for distichia only while 28 eyelids (32%) had concurrent eyelid surgery. Successful treatment was defined as resolution of clinical signs attributable to distichiasis. Twenty‐five dogs (96%; 84 eyelids) were successfully treated with a single treatment (mean follow‐up 187 days). Sixty‐six eyelids (75%) had no distichia recurrence. Twenty‐two eyelids (25%) had recurrence at or near a previously treated site (mean follow‐up 186 days). Most dogs (96%) with distichia recurrence remained asymptomatic, requiring no further treatment. Transient eyelid margin pigment loss and mild to moderate eyelid swelling were noted in all treated eyelids postoperatively. One dog had significant recurrence on all eyelids requiring retreatment which resulted in focal entropion in one eyelid. Suspected treatment site infection occurred 2 days postoperatively in 2 eyes (4%). One of 4 patients with extensive treatment on all eyelids (>8 distichia per eyelid) developed qualitative tear deficiency (554 days) and responded to topical tear stimulant therapy. Conclusions: Transconjunctival thermal electrocautery is a successful, simple treatment for canine distichiasis. None.

Poster Abstract

Does tropicamide affect intraocular pressure in the healthy anesthetized guinea pigs?

F Asadi,¹ SM Rajaei,² S Tayeban¹ and N Ghazaleh³

¹Faculty of Veterinary Medicine, University of Semnan, Semnan, Iran; ²Department of Clinical Sciences, College of Veterinary Medicine, Karaj Branch, Islamic Azad University, Alborz, Iran; ³Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Semnan, Semnan, Iran

Purpose: The aim of this study was to determine the concurrent effects of tropicamide and anesthesia on intraocular pressure (IOP) in healthy guinea pigs. Methods: Twenty‐eight healthy adult guinea pigs (12 males and 16 females) were used in this study, which randomly assigned to four groups. Prior to anaesthesia, baseline IOP (T0) of each group was recorded. Then one drop of tropicamide was instilled randomly into one eye of each animal and the contralateral eye was served as control. Ketamine (30 mg/kg), midazolam (1 mg/kg), medetomidine (0.5 mg/kg) and placebo (distilled water) were administered intramuscularly to each group and IOP measurements were repeated at 10 min (T10), 30 min (T30), 60 min (T60), 120 min (T120), and 180 min (T180). Results: No significant differences were found between tropicamide treated eyes and control eyes at each time point in all groups. Mean ± SD baseline IOP of ketamine, midazolam, medetomidine and control groups was 10.14 ± 2.64, 10.57 ± 1.45,10.50 ± 1.93 and 10.07 ± 1.23 mmHg, respectively. In ketamine and midazolam groups, the IOP increased over the time; however, this increase was only statistically significant in the midazolam group (P = 0.02). Medetomidine administration decreased the IOP at all‐time points (P < 0.001). Conclusions: The present study demonstrated concurrent administration of tropicamide with ketamine and midazolam increased the IOP while medetomidine decreased the IOP significantly in guinea pigs. Increase IOP in the control and midazolam groups maybe associated with systemic effect of tropicamide. None.

Ketamine: 10%, Alfasan, Woerden, Netherlands.

Midazolame: Midamax^®, Tehranchemie Pharmaceutical Company, Tehran, Iran.

Medetomidine: Dorbene Vet, Laboratorios Syva, Leon, Spain.

Tropicamide: Mydrax^® 1%, Sina Darou, Tehran, Iran.

Ocular volume determination in normal feline eyes

F Asadi,¹ M Molazem,² Y Vali² and MH Yousefi³

¹Faculty of Veterinary Medicine, University of Semnan, Semnan, Iran; ²Department of Radiology and surgery, Faculty of veterinary medicine, University of Tehran, Tehran, Iran; ³Department of Anatomy, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran

Purpose: The object of this study was to determine the ocular volume by Three‐dimensional (3D) ultrasound and Computed Tomography (CT) in clinically normal adult Domestic Shorthair (DSH) cats. Methods: In this study, ten adult DSH cats (6 males, 4 females) weighting 3.79 ± 0.741 (mean ± SD) Kg, were used. A full physical examination was performed and cats were selected based on normal physical and ophthalmic examinations. Ocular volume using 3D Ultrasound was assessed. Then all animals were anesthetized by combination of Ketamine (Ketamine 10%, Alfasan, Woerden, Netherlands) and Midazolam (Midamax^®, Tehran Chemie Pharmaceutical Company, Tehran, Iran) injection and ocular volumetry were conducted by using CT. All data statistically were analyzed and the comparison with gender as well as the correlation with the body weight was done. Results: The mean ± SD ocular volume by 3D ultrasound and CT evaluation was 4.34 ± 0.47 cm³ and 5.36 ± 0.76 cm³, respectively. No significant difference was found between neither the right and left eyes, nor males and females in both imaging methods. There was a positive correlation between ocular volume and body weight (P‐value in 3D ultrasound and CT was 0.022 and 0.009, respectively). Conclusions: This is the first report describing the normal value of ocular volume in the cats. The results of this study would ameliorate the ability of interpretation on 3D ultrasound and CT images and would be useful for diagnosis and treatment of some ophthalmic diseases. None.

Development of a novel multi‐species ex vivo corneal fibrosis model

WM Berkowski,¹ DJ Gibson,² LR Proietto,¹ RD Whitley,¹ GS Schultz² and CE Plummer¹

¹Department of Small Animal Clinical Sciences, University of Florida, Gainesville, FL, USA; ²Institute for Wound Research, University of Florida, Gainesville, FL, USA

Purpose: To develop a multi‐species ex vivo corneal culture model in which wounded tissues predictably epithelialize and form subepithelial haze, while preserving natural radius of curvature and biomechanics of wound healing. Methods: Corneoscleral rims were harvested from clinically normal globes of dogs (n = 16 corneas) and rabbits (n = 21 corneas). Tissues were then cultured in a buffered DMEM / Ham's F‐12 based medium and maintained at 37°C and 5% CO2. The control group (dog n = 8, rabbit n = 10) contained unwounded corneas. The experimental group (dog n = 8, rabbit n = 11) contained corneas which received axial stromal wounds with an excimer laser (depth: 250 μm in dogs, 155 μm in rabbits; diameter: 6 mm). Each cornea was fluorescein‐stained and photographed every 6–12 h until full epithelialization occurred. Wound surface area (mm²) was calculated for each cornea to assess epithelialization rate. All corneas were also photographed at 0, 7, 14, and 21 days to record changes in optical clarity (haze). Results: The mean epithelialization time was 47 h in the canine experimental group and 63 h in the lagomorph experimental group. All wounded canine and lagomorph corneoscleral rims which survived for 21 days developed significant wound‐associated fibrosis, characterized by a roughly circular, diffuse, could‐like pattern of optical haze. All corneas maintained a normal radius of curvature throughout the study period, and unwounded control corneas did not develop axial haze. Conclusions: Stromal‐wounded ex vivo corneas reliably produced axial haze analogous to that of a wounded cornea in vivo. In addition, the model successfully supported tissues from two morphologically diverse species with minimal modifications. Future models may be adapted for additional species based on these results. Support: UF internal grants. None.

Corneal sensitivity and tear production after phacoemulsification in diabetic dogs

EAK Rodriguez,¹ PSJ Dongo,¹ DA Otsuki,² AMV Safatle¹ and AA Bolzan¹

¹Ophthalmology Service, College of Veterinary Medicine, University of São Paulo, Brazil; ²Laboratory of Medical Investigation/Anaesthesiology, College of Medicine, University of São Paulo, Brazil

Purpose: To evaluate corneal sensitivity and tear production after phacoemulsification in diabetic dogs. Methods: Ten diabetic dogs (1 male and 9 females) of different breeds (2 mixed breed, 2 Poodle, 2 Schnauzer, 1 Border Collie, 1 English Cocker Spaniel, 1 Labrador and 1 Lhasa Apso) ranging in age from 6 to 14 years were enrolled in this study. The conventional unilateral two‐handed phacoemulsification was performed through a 2.75 mm clear corneal incision using a Laureate machine. Central corneal sensitivity and tear production were measured by Cochet‐Bonnet aesthesiometer and Schirmer tear test, respectively, in operated and unoperated eyes (control eyes). Evaluations were performed before the surgery (basal values ‐ T0) and 7(T1), 15(T2), 30(T3), 90(T4) and 180(T5) post‐operative days. Results: Corneal sensitivity in T0 was 2.3 ± 0.6 cm for operated eyes (OE), and 2.2 ± 0.4 cm for control eyes (CE). Post‐surgical values were: OE = 1.4 ± 0.5 mm and CE = 2.2 ± 0.4 mm (T1); OE = 1.6 ± 0.6 mm and CE = 2.2 ± 0.4 mm (T2); OE = 1.5 ± 0.5 mm and CE = 2 ± 0.5 mm (T3); OE = 1.9 ± 0.3 mm and CE = 2.2 ± 0.3 mm (T4); OE = 1.7 ± 0.5 mm and CE = 2.1 ± 0.2 mm (T5). Tear production in T0 was 22 ± 2.5 mm/min for OE, and 22 ± 4.3 mm/min for CE. Post‐operative values were: OE = 20 ± 5.1 mm/min and CE = 21 ± 3.2 mm/min (T1); OE = 23 ± 5.5 mm/min and CE = 22 ± 4.2 mm/min (T2); OE = 20 ± 4.3 mm/min and CE = 22 ± 4.9 mm/min (T3); OE = 22 ± 4.8 mm/min and CE = 22 ± 5.8 mm/min (T4); OE = 22 ± 5 mm/min and CE = 24 ± 6.6 mm/min (T5). There were significant differences in corneal sensitivity values between T1 and T0, only for OE, and between OE and CE at T1 (P < 0.05). Tear production showed no differences. Conclusions: The performance of phacoemulsification in diabetic dogs causes a decrease in the corneal sensitivity in the early postoperative period. Supported by FAPESP 2010/20555‐9. None.

Intraocular pressure measured by applanation tonometry in burrowing owls (Athene cunicularia)

DG Pinto,¹ PSJ Dongo,¹ AR Eyherabide,¹ MB Guimarães,² AMV Safatle¹ and AA Bolzan¹

¹Ophthalmology Service, College of Veterinary Medicine, University of São Paulo, Brazil; ²Avian Ambulatory Service, College of Veterinary Medicine, University of São Paulo, Brazil

Purpose: The aim of this study was to determine physiological reference values for intraocular pressure (IOP) by applanation tonometry in burrowing owls (Athene cunicularia). Methods: Thirteen healthy adult owls (26 eyes) weighing 153–190 g were enrolled in this study. Ophthalmic examination was performed prior to IOP mensuration to exclude ocular diseases. IOP was obtained using applanation tonometry with the Tonopen Avia Vet^® after instillation of one drop of 0.5% proparacaine ophthalmic solution. The birds were gently manually restrained in an upright position and the manipulation of the eyelids was very careful to avoid increases in IOP. The recorded IOP was an average of three successive measurements on the central cornea with error less than 5%. The right eye was always measured first. Results: The mean ± SD values of IOP were 14.2 ± 2.4 mmHg (with a range of 11.3–19.5) for right eyes and 13.9 ± 1.2 mmHg (with a range of 12–16) for left eyes. No significant differences were observed between the left and right eyes. Conclusions: Applanation tonometry is a useful diagnostic tool to measure IOP in burrowing owls. The method was easy to perform and well tolerated by birds. The results will be useful in the diagnosis, treatment and monitoring progression of ocular diseases, such as uveitis and glaucoma. None.

Refractive states of eyes in domestic rabbits

J Burn,¹ K Combs Ramey,¹ S Chalhoub² and A Cooke¹

¹Western Veterinary Specialist and Emergency Centre; ²University of Calgary Faculty of Veterinary Medicine

Purpose: To measure the refractive state of normal domestic rabbit eyes and evaluate any relationship between refractive error and age, breed, and axial globe length. Methods: Streak retinoscopy was performed on 30 ophthalmologically normal domestic rabbits (60 eyes) to determine refractive state. Myopia was classified as refractive error measuring less than or equal to −0.5 Diopters (D) and hyperopia greater than or equal to +0.5 D. Age, gender and breed of each rabbit were recorded. Intraocular pressure (IOP) was measured in all eyes (ICare Tonovet ^®). B‐mode ultrasonography was used to determine anterior chamber depth, vitreous chamber depth, lens thickness, and axial globe length. Results: 22/30 rabbits (73%) observed in this study were emmetropic; one rabbit (0.03%) was myopic and seven (23%) were hyperopic. Mean refractive errors for right and left eyes were emmetropic: 0.2 ± 0.7 D and 0 ± 1.0 D, respectively (range −3.0 to 1.0 D). Mean anterior chamber depth, lens thickness, vitreous chamber depth and total axial length were 2.2 ± 3 mm, 7.6 ± 7 mm, 6.3 ± 4 mm, and 16.0 ± 8 mm, respectively. Mean IOP for right and left eyes were 15.60 ± 3.11 mmHg and 15.37 ± 2.91 mmHg, respectively. No statistical significance was noted between the refractive error and axial globe length of the right and left eyes (P < 0.05) as measured using B‐mode ultrasonography. Conclusions: The majority of rabbits in this study were emmetropic. There was no significant difference in refractive error between right and left eyes. Supported by University of Calgary Faculty of Veterinary Medicine Intern funds. None.

Enrofloxacin concentration in aqueous humor and humor vitreous of fetuses and foals after administration in pregnant mares

E Capistrano,¹ T Villar,² AL Pascoli,³ IF Canisso^1,2 and BC Martins^1,2

¹Department of Veterinary Medicine, University of Illinois, Champaign, IL, USA; ²Department of Biomedical Sciences, University of Illinois, Champaign, IL, USA; ³Sao Paulo State University, Jaboticabal, Brazil

Purpose: To determine the ability of enrofloxacin to cross the placenta and the ocular barriers during the last stage of pregnancy in mares, and cause ocular alterations in fetuses and foals. Methods: Enrofloxacin was given to 12 healthy mares around 250 days of gestation, at doses of 5 mg/kg IV (G1, n = 4), 7.5 mg/kg orally (G2, n = 2), 10 mg/kg IV (G3, n = 4) and 15 mg/kg orally (G4, n = 2), every 24 h for 15 days. In G1 and G3, 24 h after the last dose, parturition was induced for reasons unrelated to this study. In G2 and G4, normal parturition was performed and foals were maintained for 30 days. Fetuses and foals were humanely euthanized for reasons unrelated to this study. Both eyes were enucleated and submitted for histologic evaluation. Levels of enrofloxacin in the aqueous humor and vitreous were measured by high‐performance liquid chromatography. Results: Enrofloxacin was detected in the fetuses’ aqueous humor (G1 = 482 ± 282.2 μg/ml; G3 = 953.5 ± 670.8 μg/ml) and vitreous (G1 = 199.5 ± 38.3 μg/ml; G3 = 437.8 ± 22.3 μg/ml) of all individuals and in the foals’ aqueous humor (G2 = 1.55 ± 1.49 μg/ml; G2 = 1.1 ± 1.13 μg/ml) and vitreous (G1 = 1.25 ± 0.07 μg/ml; G2 = 2.3 ± 0.56 μg/ml) of all individuals. No histological abnormalities were detected in any individual. Conclusions: Enrofloxacin was able to cross the placenta and the ocular barriers and reach the aqueous humor and humor vitreous in fetuses and foals. However, it did not induce to any histological abnormality. Supported by Department of Veterinary Clinical Medicine Funds and USDA Hatch Funds. None.

Automated versus manual refractive error measurements in domestic cats

AM Cleymaet,¹ EN Harb,² AM Hess³ and KS Freeman¹

¹Department of Clinical Sciences, College of Veterinary Medicine, Colorado State University, Fort Collins, CO, USA; ²Department of Vision Science, School of Optometry, University of California Berkeley, Berkeley, CA, USA; ³Department of Statistics, College of Natural Sciences, Colorado State University, Fort Collins, CO, USA

Purpose: To compare the results of streak retinoscopy (SR) vs. the Welch Allyn SureSight™ autorefractor (WASS) in normal cats and determine the appropriate WASS setting (WASSadult vs. WASSpediatric) for use in the domestic cat. Methods: Refractive error was determined in 30 young adult domestic short haired cats (60 eyes) with normal, non‐cyclopleged eyes via SR. In 28 cats (56 eyes), refractive error was also determined via WASSadult. In 8 cats (16 eyes), refractive error was also determined via WASSpediatric. Refractive error was determined by both WASSadult and WASSpediatric in 6 cats (12 eyes). Agreement between methods was evaluated with Bland‐Altman analysis. Mixed modeling was used to test for difference between methods. Results: Mean ± SD SR spherical equivalent (SE) was +1.05 ± 0.97 diopters (D) (n = 60 eyes). Mean WASS SEadult was +0.60 ± 1.15 D (n = 56 eyes), and mean WASS SEpediatric was +2.75 ± 0.98 D (n = 16 eyes). The difference between methods was statistically significant for WASSadult vs. SR (P ≤ 0.001, n = 56 eyes), WASSpediatric vs. SR (P = 0.01, n = 16 eyes), and WASS_adult vs. WASSpediatric (P ≤ 0.001, n = 12 eyes). The 95% limits of agreement for WASSadult vs. SR was (−1.80 D, +0.99 D), WASSpediatric vs. SR was (−0.75 D, +3.55 D), and WASSpediatric vs. WASSadult was (−4.75 D, +0.21 D). Conclusions: While there was a significant difference between methods, the level of agreement between SR and WASSadult for measurement of refractive error in the adult domestic cat is reasonable. For WASS, adult setting is recommended for clinical use. Supported in part by the Center for Companion Animal Studies at Colorado State University. None.

Follicular choristoma in the third eyelid of an eclectus parrot (Eclectus roratus)

JE Darden,¹ AM Winkel‐Blair,¹ EE Edwards,² SM Hoppes,¹ J Mansell² and EM Scott¹

¹Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA; ²Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA

Purpose: To describe the clinical appearance and histopathological findings in an eclectus parrot with an ocular follicular choristoma. Methods: A 1‐year‐old male eclectus parrot with a 3‐month history of blepharospasm in the right eye was presented to the Texas A&M Veterinary Medical Teaching Hospital for further evaluation. The referring veterinarian plucked a suspected ectopic feather from the right eye six weeks prior to presentation. Complete ophthalmic examination with slit lamp biomicroscopy was performed. A conjunctival mass from the leading edge of the third eyelid was excised under general anesthesia and submitted for histopathology. Results: Ocular examination revealed a 3 × 2 × 2 mm raised vascular mass with a focally pigmented center associated with the temporal aspect of the leading edge of the third eyelid. Histologically, there was a single, pigmented feather follicle bulb surrounded by multiple, discrete lymphoid follicles and moderate lymphoplasmacytic inflammation within the substantia propria of the third eyelid conjunctiva. The discovery of the histologically normal feather follicle in an abnormal location classifies the lesion as a choristoma. Five months after surgery the parrot had no signs of discomfort or regrowth of the feather follicle. Conclusions: This study has identified a previously unreported lesion caused by normal differentiation of an ectopic feather follicle in the third eyelid of an eclectus parrot. Though rare, the presence of a choristoma should be considered as a differential for avian patients with blepharospasm. None.

Photobiomodulation for treatment of idiopathic facial nerve paralysis in a dog

DD Dees

Eye Care for Animals, Austin, TX, USA

Purpose: To describe a novel method for treatment of facial nerve paralysis in a dog. Methods: Photobiomodulation (Low‐level laser therapy) was performed on a 10‐year‐old neutered male Cavalier King Charles Spaniel with right‐sided idiopathic facial nerve paralysis. Informed owner consent was obtained prior to treatment. The laser unit (GradyVet P‐3000; Class 3b; 810 nm) utilized a precision single‐diode trigger point probe (500 mW) with the dose calculated by accompanying software. A total of four sites were treated corresponding to the acupuncture points Gall Bladder‐1, 2, 3 and Triple Heater‐17. These points correlated with the anatomic position of the auriculopalpebral branch of the facial nerve. Laser settings were continuous wave, 500 mW, 32 s at each site. Treatments were performed twice weekly for five weeks. Results: Initial ophthalmic examination showed complete absence of palpebral reflex, moderate upper eyelid ptosis, mild neurotrophic keratitis, and Schirmer tear test‐1 (STT‐1) value of 17 mm/min OD. After ten treatments, the upper eyelid ptosis and axial corneal dryness resolved. STT‐1 value improved to 21 mm/min. Blinking ability was improved allowing for 50% coverage of the cornea. Patient follow up at 3 and 6 months showed stability in blinking ability. Conclusion: In this case, photobiomodulation was successful in improvement of blinking ability and STT‐1 values in a dog with unilateral facial nerve paralysis. None.

Unilateral anterior segment dysgenesis (Peters’ Anomaly) and bilateral eyelid agenesis in a 5‐year‐old female spayed domestic shorthair: a case report

SS Erlichman,^1,2 KM Burgesser¹ and RE Merideth²

¹Veterinary Specialists and Emergency Services, Rochester, NY, USA; ²Eye Care for Animals, Southern Arizona Veterinary Specialty & Emergency, Tucson, AZ, USA

Purpose: To describe the clinical appearance of a case of unilateral anterior segment dysgenesis and bilateral eyelid agenesis in a feline using biomicroscopy and indirect ophthalmoscopy. Methods: A 5‐year‐old FS Domestic Shorthair presented to Veterinary Specialists and Emergency Services for re‐evaluation of an axial corneal opacity OD and eyelid agenesis of the superior lids OU. Routine ophthalmic examination using slit lamp biomicroscopy and indirect ophthalmoscopy was performed to accurately describe the lesions. The feline was initially evaluated in 2012 after bilateral Hotz Celsus by a referring veterinarian, and at this time cryoepilation of superior lid trichiasis OD was performed with nitrous oxide cryoprobe. Results: Ophthalmic evaluation revealed the patient to be bilaterally visual with normal neuro‐ophthalmic exam. The right eye had eyelid agenesis affecting ˜ 50% of the lateral aspect of the superior lid. The anterior chamber was shallow with adhesions between the anterior lens capsule and the axial corneal endothelium. An immature axial anterior cortical cataract was present as well as iris‐to‐iris persistent pupillary membranes. Complete fundic examination was obscured axially, but overall appeared normal. The left eye showed eyelid agenesis involving ˜30% of the lateral superior lid, and otherwise normal ocular exam. Conclusion: This is a case with multiple congenital anomalies, arising from different embryonic layers; the anterior segment dysgenesis arose from abnormal differentiation of the neural crest cells, while eyelid agenesis arose from a defect in development of the surface ectoderm. To the authors’ knowledge, this degree of severity of anterior segment dysgenesis, Peters’ Anomaly, in combination with eyelid agenesis, is relatively uncommon. None.

Small manual incision surgery for anterior lens luxation in dogs

JM Freundt

Unidad de Oftalmología Veterinaria UNOVE, Lima, Perú

Purpose: To demonstrate small manual incision surgery for anterior lens luxation in dogs as a novel treatment alternative. Methods: 7 dogs (3 Poodles, 2 Shih tzús, 2 mixed breed dogs), 3 males and 4 females, between 8 to 10 years of age, were included. The anteriorly luxated lenses were cataractous in all 7 eyes, these cataracts were mature in 5 of the eyes. Other than the anterior lens luxation, the eyes had to be normal according to UNOVE standards when evaluated as follows in order to be included: Slit lamp biomicroscopy, Schirmer tear test, tonometry, ocular ultrasonography (12 MHz), and electroretinography. The surgical procedure began with a 6–7 mm conjunctival incision, followed by a 3‐mm scleral tunnel 1.5 mm behind the limbus. Subsequently, the inner cornea was penetrated to enter the anterior chamber. The lens was slowly removed from the anterior chamber with a lens loop while the posterior lip of the tunnel was depressed. Once the lens was removed the internal scleral and external conjunctiva were sutured with 8‐0 polyglactin 910. Corneal edema, intraocular pressure and Tyndall effect were evaluated 24, 48 and 72 h post‐surgery, then 7, 30 and 60 days post‐surgery. Results: 1/7 eyes developed diffuse corneal edema post‐surgery which lasted one week, 1/7 eyes developed acute glaucoma 48 h after surgery. Conclusions: Small manual incision surgery technique is an effective method for treatment of anterior lens luxation in dogs. None.

A preliminary clinical trial for evaluation of the therapeutic effects of a tear substitute containing 0.1% polyvinyl alcohol, 0.3% sodium hyaluronate, and 5% dodecahydrosqualene in dogs with corneal ulcers

T Hasegawa,¹ S Tanaka¹ and S Sawa²

¹Osaka Prefecture University, Osaka, Japan; ²Senju Pharmaceutical CO. LTD., Kobe, Japan

Purpose: A tear substitute containing 0.1% polyvinyl alcohol (PVA), 0.3% sodium hyaluronate (SH), and 5% dodecahydrosqualene (DHS) was preliminarily evaluated on canine corneal ulcers (CUs) which had not healed by conventional treatments using antibiotics and/or autologous serum. Methods: Six canine CUs which did not respond to conventional treatments were used. Four dogs had superficial CUs associated with cataract surgery (case 1; duration of CU: 10 days without healing), radiation therapy (case 2; 2 days with worsen condition), evisceration with intraocular prosthesis (EIP) (case 3; 1 month without healing), and removal of the anterior luxated lens (case 4; 45 days without healing). The other two dogs had stromal CUs related to EIP (case 5; 33 days without healing), and due to an unknown cause from an autoimmune mediated disease (case 6; 3 days with worsen condition). The conventional treatments were replaced by application of the substitute and additional antibiotics 4 times per day. Results: All cases of superficial CUs were cured with the treatment of the substitute and antibiotics within 7–12 days (cases 1–3) or 52 days (case 4). The treatment also resulted in healing within 2 months in case 5. In case 6, improvement of the lesion was observed after 1 week of replaced treatment, but cure of the lesion could not be confirmed because of sudden death. Conclusions: The 0.1% PVA/ 0.3% SH/ 5% DHS tear substitute is available as an adjunctive drug for treating canine CUs in addition to its use for keratoconjunctivitis sicca. None.

Sebaceous carcinoma in a Bengal tiger (Panthera tigris tigris) in captivity

A Iaquinandi,¹ F Lois,² M Falzone² and P Sande¹

¹Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, School of Medicine/CEFYBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina; ²Temaiken Foundation, Escobar, Buenos Aires, Argentina

Purpose: To describe the first case of a sebaceous carcinoma in the caruncle area of a Bengal tiger (Panthera tigris tigris) in captivity. Methods: A 16‐year old zoo‐kept intact male tiger was examined with an ulcerated and bleeding mass of 1.5 mm in diameter located on the left eye caruncle. The mass was completely removed under general anesthesia by a medial canthoplasty at one week after the initial presentation. Recheck examinations were performed on days 3, 5, 15, and 30 and 18 months after surgery. Results: Histological evaluation confirmed the diagnosis of sebaceous carcinoma. There were no recurrences at 1.5 years after surgery. Conclusions: This is the first case of a sebaceous carcinoma in a tiger in captivity described in South America, and the first in an atypical anatomic location (caruncle) which was early and successfully removed. There was no recurrence at 1.5 years. None.

Anatomical features of the optic canal and the cephalic index in the cranial bone of healthy dogs

Y Ichikawa¹ and N Kanemaki^1,2

¹Department of Veterinary Medicine, Azabu University, Sagamihara, Japan; ²Veterinary Teaching Hospital, Azabu University, Sagamihara, Japan

Purpose: We studied the anatomical features of the optical canal among brachycephalic, mesocephalic, and dolichocephalic dogs, which are characterized by cephalic indexes, by analyzing computed tomography (CT) images of the head in healthy dogs. Methods: Thirty‐two adult healthy dogs were divided into three groups. The eight brachycephalic dogs included three Cavalier King Charles spaniels, two French bulldogs and Chihuahuas, and one Shih Tzu. The 13 mesocephalic dogs included four American cocker spaniels and Cardigan Welsh corgis, two toy poodles and Yorkshire terriers, and one Labrador retriever. The 11 dolichocephalic dogs included nine miniature dachshunds, one Great Dane and Shetland sheepdog. OsiriX Lite software (v.8.0.2, Picmeo SARL, Switzerland) was used to measure the length and diameter of the optic canal and the angle of the paired canals, and cephalic index, with the CT images of the heads. Values among the groups were analyzed using a post‐hoc test. Results: Stockard's and Evans's cephalic index in the brachycephalic group were 94.3 ± 13.7 and 79.4 ± 12.0, respectively, and significantly higher than those of the mesocephalic and dolichocephalic groups. The angle of paired canals in the brachycephalic, mesocephalic, and dolichocephalic groups was 103.1 ± 12.8, 82.9 ± 8.1, and 79.7 ± 5.7 degrees, respectively. There was a positive correlation between the angle of optic canals and the cephalic index. There was no significant difference in the length and diameter of the optic canal among the groups. Conclusions: The positioning of the optic canal varies with cranial morphology in dogs. None.

Fibrin glue obtained from concentrated self‐plasma for treating chronic superficial corneal problems in senior dogs

M Inaniwa,¹ Y Ichikawa,¹ K Terakado² and N Kanemaki^1,2

¹Department of Veterinary Medicine, Azabu University, Sagamihara, Japan; ²Veterinary Teaching Hospital, Azabu University, Sagamihara, Japan

Purpose: To evaluate and compare the fibrinogen levels concentrated from plasma using a rapid method and a conventional procedure, and to apply the fibrin glue, obtained from concentrated self‐plasma using the rapid method, for treating chronic corneal problems in senior dogs. Methods: Concentrated plasma fibrinogen was obtained using a conventional procedure and a rapid method. The conventional procedure involved 2 freeze‐thaw cycles over 2 consecutive nights. The rapid method involved several freeze‐thaw cycles of citrated plasma in 1 h. The plasma fibrinogen level was measured using a sandwich enzyme‐linked immunosorbent assay. In this study, we included 10 dogs aged over 10 years, including those with chronic superficial corneal ulcers (n = 6) and chronic non‐ulcerative keratitis (n = 4). The fibrin glue was made by mixing concentrated self‐plasma fibrinogen and calcium‐thrombin solution, and was applied onto the cornea. The outcome of fibrin glue treatment was evaluated by scoring the clinical findings using a contingency table test. Results: The level of concentrated fibrinogen obtained using the rapid method (930.8 ± 106.2 mg/dl) was comparable to that obtained using the conventional method (968.0 ± 99.6 mg/dl), and was 1.39 times higher than the control plasma level (670.3 ± 22.8 mg/dl). In dogs with chronic corneal problems, the corneal surface roughness was promoted, as shown by slit‐lamp biomicroscopic images, although the times and periods of fibrin glue treatment varied between 1–8 times and 7–210 days, respectively. However, no other remarkable finding was observed. Conclusion: Fibrin glue produced using the rapid method may be useful for treating chronic corneal problems. None.

Presence of serum antibodies against two synthetic peptide fragments of SRBD1 in Shiba Inu dogs with glaucoma

N Kanemaki,^1,2 M Fujita,² Y Goto,¹ M Inaniwa,¹ K Terakado,¹ Y Ichikawa,² A Meguro³ and N Mizuki³

¹Veterinary Teaching Hospital, Azabu University, Sagamihara, Japan; ²Department of Veterinary Medicine, Azabu University, Sagamihara, Japan; ³Department of Ophthalmology, Yokohama City University School of Medicine, Yokohama, Kanagawa, Japan

Purpose: Serum autoantibodies against retinal proteins have been detected in patients with glaucoma. Recently, we reported single‐nucleotide polymorphisms in SRBD1 (S1 RNA binding domain 1) that were associated with glaucoma in Shiba Inu dogs. Therefore, we examined serum antibodies against synthetic peptide fragments of SRBD1 in Shiba Inu dogs with glaucoma. Methods: Enzyme‐linked immunoassay (ELISA) was used to measure the titers of serum antibodies against synthetic peptide fragments, SQ15214: ¹MSSLPRRAKVKVQAVVSKD¹⁹ and SQ15215: ⁵²KQPVAKESKPKRVPRVK,⁶⁸ of SRBD1 (Accession number: XP_854655.2) in 36 Shiba Inu dogs. Normalization between plate measurements was performed using a mixture of serum from six healthy beagle dogs as a measure of pooled serum antibody titer. Antibody titers were compared using the Wilcoxon test. Rabbits were immunized with the two peptide fragments, to express antibodies (IgG) against them, which were then subjected to Western blot analysis to determine their localization in immunoreactive ocular tissue. Results: The serum titers of anti‐SQ15214 and anti‐SQ15215 antibodies in 26 Shiba Inu dogs with glaucoma were significantly lower than that of antibodies in 10 healthy Shiba Inu dogs (P < 0.05). There was no significant difference between the ages and serum titers of male and female dogs. Rabbit anti‐SQ15214 and anti‐SQ15215 antibodies were detected for a protein of 45.9 kDa in the iris/ciliary bodies and serum, but not in the retina. Rabbit anti‐SQ15214 reacted with two proteins of 36.2 and 45.9 kDa in optic nerve. Conclusions: SRBD1 may be specifically associated with serum autoantibodies in Shiba Inu dogs with glaucoma. Supported by JSPS KAKENHI Grant Number JP26450436. None.

Topical 5 fluorouracil as adjuvant therapy for ocular fibropapilloma tumors in green sea turtles (Chelonia mydas)

LG Karpinski,¹ B Zirkelbach,² OJ Carlile² and JN Pescatore²

¹Pinecrest Veterinary Hospital; ²The Turtle Hospital

Purpose: 5‐Fluorouracil (5FU), an antimetabolite chemotherapeutic agent, formulated as a 1% topical ophthalmic solution, was used to treat 204 Green Sea Turtle eyes (107 turtles) after surgical removal or debulking of ocular and periocular fibropapilloma (FP) tumors. Methods: Treatment consisted of twice daily application of 5FU for 6–8 weeks post surgical tumor removal. Turtles were kept for observation at least 9 months from the time of tumor removal. Results: Eighty‐eight of 107 turtles had no recurrence of eye tumors. Forty‐five turtles were released and 10 turtles are still in rehabilitation. Fifty‐two turtles died or were euthanatized due to systemic appearance of fibropapilloma tumors within the time of observation. Nineteen turtles had regrowth of ocular tumors. Conclusions: 5FU adjuvant therapy improves the visual outcome and chance for release of turtles affected with bilateral ocular FP tumors compared to previous treatment protocols. None.

Assessment of meibomian glands morphology using non‐contact meibography in Shih Tzu dogs with or without keratoconjunctivitis sicca

Y Kitamura,^1,2 S Maehara,² T Nakade,² H Iwashita,⁵ Y Miwa,³ R Arita^3,4 and A Saito^2,5

¹Yakumo Animal Hospital, Hokkaido, Japan; ²Rakuno Gakuen University, Hokkaido, Japan; ³Keio University, Tokyo, Japan; ⁴Itoh Clinic Saitama, Japan; ⁵Triangle Animal Eye Clinic, Tokyo, Japan

Purpose: To investigate, using non‐contact meibography, meibomian gland (MG) morphology in Shih Tzu dogs with keratoconjunctivitis sicca (KCS). Methods: Fourteen eyes of 12 Shih Tzus presented to Yakumo Animal Hospital and Triangle Animal Eye Clinic from 2011–2017, and with clinical sighs and Schirmer tear test (STT) results consistent with KCS (<10 mm/min) were examined. Their mean (range) age was 10.7 (7.7–13) years. Twenty‐eight eyes of 16 Shih Tzus with normal eyes and STT >18mm/min served as controls. Their mean (range) age was 12.4 (10–15) years. Both groups of dogs underwent routine slit lamp biomicroscopy followed by meibography of the upper eyelid using SL‐D (Topcon Japan) and Meibopen (JFC Japan). Results: Meibography revealed morphological changes in the MGs of 13 eyes of 11 dogs with KCS. These included MG atrophy in 64%, and loss of glandular structure in 64% of 14 eyes. Morphological changes were also seen in the MGs of 11 dogs in the control group. This included atrophy in 50%, and loss of glandular structure in 21% of 28 eyes. Loss of a glandular structure was significantly more common in dogs with KCS than control dogs (P < 0.05). Conclusions: Altered MG structure occurs commonly in Shih Tzus with KCS. This suggests that altered tear quality and associated increased evaporation and decreased retention of tears probably compounds decreased tear volume in patients with aqueous deficiency. None.

Effect of 0.15% sodium hyaluronate on tear film break up time of healthy cats, before and after general anaesthesia

GM Madruga,¹ AP Ribeiro,² TB Magalhães,² JA Kleiner,³ LA Rondelli² and LR Martins²

¹Post graduate student of Veterinary Surgery, Sao Paulo State University (UNESP), Jaboticabal, SP, Brazil; ²Department of Veterinary Clinical Medicine and Surgery, College of Veterinary, Federal University of Mato Grosso (UFMT), Cuiabá, Brazil; ³Vetweb Oftalmologia Veterinária, Curitiba, Brazil

Purpose: This study aimed to evaluate the effect of 0.15% sodium hyaluronate (SH) on tear film break‐up time (TFBT) before and after general anesthesia in healthy cats. In addition, possible correlation between the conjunctival goblet cell density (GCD) and TFBT of non‐anesthetized cats was checked. Methods: In 13 non‐anesthetized cats, TFBT was assessed at baseline and following 1, 10, and 20 min of the instillation of SH. In another 39 cats, TFBT was measured at the end of the anesthesia (T40) and following, 35 (T75) and 80 min (T120) of the end of the anesthesia. Analysis was performed using ANOVA followed by Tukey's test or Bonferroni's test and Person′s correlations test (P < 0.05) Results: SH did not increase TFBT in non‐ anesthetized cats at any time point (P = 0.33). GCD correlated positively with TFBT (P = 0.02; r = 0.60). TFBT decreased significantly in control eyes at all time points after anesthesia, when compared with baseline of non‐anesthetized cats (P < 0.001). TFBT increased significantly in SH‐treated eyes, only at T40 after anesthesia, when compared with baseline of non‐anesthetized cats (P < 0.0001). In anesthetized cats, TFBT assessed in SH‐treated eyes were significantly higher in comparison with control eyes at all time points (P < 0.001). Conclusions: It can be conclude the SH should be instilled every 60 min during anesthesia, and for more than 80 min following the end of anesthetic procedures in healthy cats. Support/Disclosure: None.

Effects of the 0.15% sodium hialuronate and 0.5% carboxymethylcellulose on tear film breakup time in dogs with keratoconjunctivitis sicca and in healthy dogs

GM Madruga,¹ AP Ribeiro,² TB Magalhães,² JA Kleiner³ and AL Souza⁴

¹Sao Paulo State University (UNESP), Jaboticabal, SP, Brazil; ²Department of Veterinary Clinical Medicine and Surgery, College of Veterinary, Federal University of Mato Grosso (UFMT), Cuiabá, Brazil; ³Vetweb Oftalmologia Veterinária, Curitiba, Brazil; ⁴Clinivet Hospital Veterinário, Curitiba, Brazil

Purpose: This study aimed to evaluate the effect of the 0.15% sodium hyaluronate (SH) and of 0.5% carboxymethylcellulose (CMC) on tear film breakup time (TFBUT) in 10 healthy dogs and in 32 eyes of dogs with keratoconjunctivis sicca (KCS). In addition, the goblet cell density (GCD) of this population was quantified. Methods: TFBUT was assessed at baseline and at different time points following the instillation of SH and CMC. The TFBUT was performed following the instillation of one drop of 0.1 ml of 1% sodium fluorescein at the dorsal bulbar conjunctiva. KCS was graded as mild, moderate and severe. GCD was quantified from conjunctival biopsies. Data were assessed with ANOVA followed by Tukey's test or Bonferroni's test and Person′s correlations test (P < 0.05). Results: The number of GCD differed significantly between patients with mild and moderate KCS (P < 0.01). TFBUT of healthy dogs increased only at 1 min after treatment with SH (P < 0.01). Regarding baseline and treatments, SH significantly increased TFBUT for up to 30 min on the ocular surface, in comparison to CMC, in all categories of KCS (P < 0.01). TFBUT and GCD correlated positively when the healthy and diseased eyes were grouped (r = 0.41, P = 0.006). Conclusions: It can be concluded that in dogs with KCS, SH lasts longer periods on the ocular surface than CMC, but such agents does not increase TFBUT in healthy dogs. Such findings suggest that immune‐mediated KCS of dogs tends to shift from quantitative to quali‐quantitative disorder as the disease progresses. None.

In vivo confocal microscopy characteristics of equine epithelial and subepithelial nonulcerative keratomycosis

EC Ledbetter,¹ NL Irby¹ and LB Teixeira²

¹Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca NY, USA; ²Department Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin‐Madison, Madison, WI, USA

Purpose: To described the in vivo confocal microscopy features of horses with epithelial and subepithelial nonulcerative keratomycosis. Methods: Four horses with a clinical diagnosis of epithelial or subepithelial keratomycosis were examined on one or more occasions by in vivo laser scanning confocal microscopy of the cornea. Results of confocal microscopic examinations were correlated with clinical, cytological, histopathological, and microbiological findings. Results: All horses had an irregular corneal epithelial surface during slit‐lamp biomicroscopy examination. Epithelial or subepithelial corneal opacities were present in multifocal or diffuse patterns. Rose bengal corneal staining was focally or diffusely positive in all cases. Fungal hyphae were detected in cytological or histopathological corneal samples. Aspergillus, Fusarium, and Penicillium spp. were cultured from samples. In horses with epithelial clinical disease, hyphae were diffusely distributed over the axial cornea. Fungal hyphae were seen in all layers of the corneal epithelium and associated with disorganized epithelial cells and minimal leukocyte infiltrates. Subepithelial keratomycosis was correlated with focal, dense accumulations of hyphae in the immediate subepithelial anterior stroma. The hyphae were surrounded by moderate numbers of leukocytes. Two horses were examined by confocal microscopy on multiple occasions during the course of medical therapy and fungal hyphae were observed to migrate from the epithelium into the subepithelial stroma as the clinical corneal disease progressed. Conclusions: With in vivo confocal microscopy, both epithelial and subepithelial keratomycosis appear as unique clinical entities. Equine epithelial keratomycosis is a potential precursor to subepithelial keratomycosis. None.

Investigation of histopathology and locations of eyelid tumors in 120 dogs

LN Wei,¹ JY Cheng,² WH Chien² and CT Lin^1,2*

¹Institute of Veterinary Clinical Science, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan; ²Department of Ophthalmology, National Taiwan University Veterinary Hospital, Taipei, Taiwan

Purpose: To analyze clinical characteristics, locations and histopathology of eyelid tumors cases in 120 dogs. Methods: We collected canine eyelid tumors diagnosed at the National Taiwan University Veterinary Hospital (NTUVH) and Vision Eyecare Center for Animals (VECA) between 2012 and 2017. All eyelid tumors of 120 dogs were surgically excised and the excised specimens were submitted for histopathological analysis. All specimens were initially stained with H&E and additional staining was performed if more tumor information was needed. Clinical data including breed, age, gender, prevalence, treatment, tumor types, locations of tumor onset were also analyzed. Results: No significant difference of eyelid tumors was found between female and male dogs. The average age of eyelid tumors at diagnosis was 9.38 years. Benign tumors largely predominated over malignant ones, representing 83% of all cases in this study. The 3 most frequent tumor types were epithelioma (32%), meibomian gland adenoma (25%), and meibomian gland hyperplasia (21%). Predilected locations of eyelid tumors in the patients were analyzed. We found that eyelid tumors involved the upper eyelid in 62% of patients. The most common site of tumor involvement was in the upper lateral lid (32%), followed by upper central lid (20%), lower medial lid (15%), lower central lid (14%), upper medial lid (11%), and lower lateral lid (8%). Conclusions: Eyelid tumors are common in senile dogs. 83% of eyelid tumors are benign, and the leading tumor types are meibomian gland adenoma, hyperplasia, and epithelioma. The location incidence of the eyelid tumors of the canine patients may reflect the incidence of causing clinical signs by eyelid tumors to draw owners’ attention and seek medical assistance. No conflict of interest.

*Presenting author.

Investigation of pattern and severity of posterior capsular opacification in rabbits with pseudophakic and aphakic eyes

YF Chang^1,2 and CT Lin^1,2*

¹Institute of Veterinary Clinical Science, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan; ²Department of Ophthalmology, National Taiwan University Veterinary Hospital, Taipei, Taiwan

Purpose: The purpose of this study was to compare the pattern and severity of posterior capsular opacification (PCO) between implanting injectable canine IOL, human IOL, and aphakic eyes in a rabbit model. Methods: Phacoemulsification surgeries were performed OU (n = 7) in rabbits. One group of rabbits (n = 3) implanted canine IOL‐ CLV12 (Cara™ Life, Inc.) in one eye, the other group (n = 4) implanted human IOL Akreos^® Adapt (Bausch & Lomb). The contralateral eye was aphakic (n = 7). 8 weeks post‐surgeries, photos were recorded under Miyake‐Apple view. Gross PCO scores were calculated by multiplying the density of opacification (graded from 0 to 4) by the percentage of capsule area that PCO involved. Gross PCO scores of central capsule (under IOL optic or central 6.0 mm area) and peripheral region were calculated respectively. Histological analysis was performed to evaluate pathological changes of PCO. Results: Gross PCO scores listed in order as below: (1) periphery of aphakic eyes > (2) periphery of pseudophakic eyes > (3) central of aphakic eyes > (4) central of pesudophakic eyes. Statistical differences were showed between (1) (2) (1) (3) and (2) (4) groups. Histopathological evaluation confirmed the space‐occupying effects by IOLs. Anterior‐ posterior capsular adhesion in aphakic eyes formed a strong barrier of lens epithelium cells (LECs) migration, however, capsular wrinkling was obvious. Conclusions: This study confirmed the PCO inhibitory effect by IOL, especially in peripheral capsule. Despite the central PCO score of aphakic eyes were low, capsular wrinkling was more evident in comparison to pseudophakic eyes. None.

The effects of generalized oxidative stress on retina and intraocular pressure in rats

CL Pai,^1,2 SL Lin,¹ CJ Chen,¹ HJ Lin³ and CT Lin⁴*

¹Department of Veterinary Medicine, National Chung Hsing University, Taipei, Taiwan; ²Vision Eyecare Center for Animals, Taipei, Taiwan; ³China Medical University, Taipei, Taiwan; ⁴Institute of Veterinary Clinical Science, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan

Purpose: The aim of the study was to investigate the effects of generalized oxidative stress on retina and intraocular pressure (IOP) in rats. Methods: A rat model of oxidative stress was induced by low dose D‐galactose (100 mg/kg, SC, sid) for 8 weeks. We investigated behavior, images of fundus morphology, optical coherence tomography (OCT) of anterior chamber and retina in the test rats at the beginning and ending of induction. IOP was measured every week. The serum profile of antioxidants and peroxidants was analyzed at pre‐induction, every 2 weeks post induction. In addition, Müller's cells, astrocytes, microglial, and iNOS of the rat eyes were immunolabeled with GFAP, Iba‐1 and iNOS. The locations and amounts of the retinal glial cells and iNOS were analyzed. Results: The behavior of spatial memory ability and muscular endurance were impaired judged by 3 types of behavior tests. These behavior signs were exacerbated by induced oxidative stress. The activities of SOD and the concentration of NO in serum were decreased after induction. Elevated IOP was noted, but angle‐closure glaucoma was excluded by anterior segment‐optical coherence tomography (AS‐OCT). Immunohistochemical (IHC) stains showed that increased expression of Müller's cells, astrocytes and microglia post induction. Microglia mostly became active. The location of iNOS was mainly in the retinal inner nuclear layer and some appeared in ganglion cell layer and retinal pigment epithelium of the retina. Conclusion: The data indicate that generalized oxidative stress resulted in impairment of behavior, increased resistance of aqueous outflow leading to elevated IOP, increased iNOS in the eye, increased expression of Müller's cells, astrocytes and microglia in the rat model. The mechanism of elevated IOP requires further investigation. None.

Bandage lens induced eosinophilic keratitis in a cat

FMA Nachtegaele

DAP Nachtegaele, Izegem, Belgium

Purpose: To describe a case of eosinophilic keratitis in a cat occurring after application of a bandage lens on the cornea. Methods: A 10‐year‐old male neutered domestic shorthair cat was referred for a chronic indolent ulcer of the right eye. Ophthalmic examination of the right eye revealed blepharospasm, conjunctival hyperaemia, superficial ulceration with loose epithelial edges of the medial cornea, superficial and stromal vascularization of the lateral cornea and central corneal degeneration. The ulcer was debrided under local anaesthesia with a cotton‐tipped applicator and a bandage lens was applied. Topical 0.1% diclofenac and 1% chloramphenicol were prescribed every 8 h for the right eye. Results: Two weeks later no discomfort was reported but a pink‐white diffuse opacity was seen encompassing the lateral cornea of the right eye. The bandage lens was removed and a white coloured tissue was noted on the inside of the lens. Impression smear cytology of the bandage lens revealed an abundant amount of eosinophils. A diagnosis of eosinophilic keratitis was made and treated with topical dexamethasone QID. Two weeks later the eosinophilic keratitis had resolved, no fluorescein uptake was noted on the cornea of the right eye. Superficial vascularization of the cornea remained but the right eye was comfortable. Conclusions: In this case the bandage lens seems to initiate or exacerbate the eosinophilic keratitis. The condition was successfully treated with topical corticosteroids and removal of the bandage lens. None.

Efficacy of long‐term topical flurbiprofen in limiting posterior capsular opacification following phacoemulsification in dogs – a pilot study

GM Newbold, T Chen, DA Ward and DVH Hendrix

Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA

Purpose: To assess posterior capsular opacity (PCO) following phacoemulsification in dogs receiving long‐term ophthalmic flurbiprofen as compared to placebo. Methods: Prospective, randomized, masked clinical study assessing two groups of dogs (flurbiprofen Group‐F versus artificial tears Group‐A) for six months following phacoemulsification. Complete eye exam and photographs were undertaken at each visit, beginning 3 weeks post‐surgery, and repeated at 2, 3, and 6 months post‐surgery. Post‐operative treatment protocols were similar for each group, except that Group F received topical flurbiprofen once a day for 6 months and Group A received artificial tears once a day for 6 months. Digital photographs were analyzed for PCO using a subjective grading scale (0–4+). For this pilot study, the change in PCO from 3 weeks to 6 months post surgery was evaluated for each dog, and the groups were compared for statistically different findings. Results: There were 13 dogs evaluated at 6 months, with eight dogs in Group A and 5 dogs in Group F. The mean initial score for Group A was 0.94 and Group F was 1.1. The mean change in subjective PCO score for group A was 0.5, and was 0.2 for group F at six months post‐surgery. There was no statistically significant difference between the groups at 6 months. Conclusions: Topical flurbiprofen applied once daily for 6 months following phacoemulsification does not appear to lead to a decrease in PCO formation. Larger group size and a prolonged follow up period may be warranted. Support/Disclosure: None.

Histopathologic and ultrastructural characterization of uveal eosinophilic material present in two cases with equine recurrent uveitis

SG Pryor,¹ KE Myrna,¹ SGM Kirejczyk² and KP Carmichael²

¹Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA; ²Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA

Purpose: To describe intraocular uveal eosinophilic material in two horses diagnosed with Equine Recurrent Uveitis (ERU) using histopathology and electron microscopy (EM). Methods: A 19‐year old Appaloosa gelding and 14‐year old Quarter horse gelding were enucleated due to unilateral corneal ulceration and blindness secondary to chronic intraocular inflammation from ERU, and severe uveitis refractory to therapy, respectively. Affected eyes were surgically removed, fixed intact in Davidson's solution and examined histologically. In addition, tissues were submitted for EM. Results: Microscopically, the clinical diagnosis of ERU was confirmed. Both cases contained abundant homogenous eosinophilic, congophilic material, consistent with amyloid, on the surface of and replacing the non‐pigmented epithelium of the ciliary body and processes. Both samples exhibited apple‐green birefringence under polarized light. EM of the affected non‐pigmented epithelium of both horses revealed extracellular deposits of non‐branching fibrils (7–15 nm in diameter), consistent with amyloid. Conclusions: The uveal eosinophilic material seen in cases of ERU has been characterized as amyloid. A recent case report (Ostevik et al) that detected amyloid in ERU cases using histopathology and immunohistochemistry further supports our conclusions. The electron microscopic appearance of amyloid in cases of ERU has not been previously described. None.

Comparison of conjunctival microbiota of clinically normal Persian cats with and without nasolacrimal duct obstruction

G Aftab,¹ SM Rajaei,² F Arfaee¹ and H Faghihi¹

¹Department of Clinical Sciences, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran; ²Department of Clinical Sciences, Department of Clinical Sciences, College of Veterinary Medicine, Karaj Branch, Islamic Azad University, Alborz, Iran

Purpose: This study was performed to determine conjunctival microbiota of Persian cats with and without nasolacrimal duct obstruction. Methods: Forty eyes of 20 clinically normal Persian cats were used [15 with bilateral nasolacrimal obstruction (Group A) and 5 without nasolacrimal obstruction (Group B)]. For the collection of specimens, a sterile swab applicator was used. Immediately after sample collection, culture was initiated. For detection of Mycoplasma spp. and feline herpesvirus 1(FHV‐1), PCR was performed on conjunctival swab and blood samples, respectively. Results: Six cats (40%) from Group A and two cats (40%) from Group B were Mycoplasma spp. positive based on the PCR results. FHV‐1 was detected on 2 cats in Group A. Moreover, fungal culture was positive in one eye (20%; Aspergillus spp.) from Group B and six eyes (40%) from Group A. The most dominant isolated fungus was Aspergillus spp. (4 of 6; 66%). Other isolated fungi were Leucosporidium spp. and Alternaria spp. Twenty‐six eyes (86.6%) were observed to have positive bacterial culture in Group A, while all the eyes had positive bacterial culture in Group B. The most commonly isolated bacterial organisms in Group A were Staphylococcus epidermidis (10/23; 40.1%), β‐hemolysis streptococcus spp. (4/23; 17.6%), Corynebacterium spp. (4/23; 16.6%), Staphylococcus aureus (3/23; 16.6%) and Escherichia coli (2/23; 10.7%), respectively. In Group B, Staphylococcus epidermidis and Staphylococcus aureus were the most isolated organisms, respectively. Conclusions: Results of this study reveal more positive fungal and bacterial cultures in the Persian cats with nasolacrimal obstruction compared to clinically normal Persian cats. None.

Seasonal effects on the conjunctival microflora of clinically normal Persian cats

G Aftab,¹ SM Rajaei,² H Faghihi¹ and M Ansari‐mood¹

¹Department of Clinical Sciences, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran; ²Department of Clinical Sciences, College of Veterinary Medicine, Karaj Branch, Islamic Azad University, Alborz, Iran

Purpose: This study was performed to determine normal aerobic and an‐aerobic bacterial flora of the cornea and conjunctiva in Persian cats. Methods: Thirty eyes of 15 clinically normal Persian cats were evaluated. All the cats lived in the same environment with constant diet for the whole year. No medication was used for the cats and no disease was observed in them one month prior to each microbial sampling. The cats were not exposed to other cats during the study period. Microbial samplings were performed at the same time on the 1st day of the second month of each season. For the collection of specimens, a sterile swab applicator was used while avoiding contact with the surrounding skin or hair. Immediately after sample collection, microbiologic aerobic and anaerobic culture was initiated. Results: Gram‐positive bacteria were observed as the most prominent isolated bacteria. In all the seasons, the most commonly isolated bacterial organisms were Staphylococcus epidermidis (41/120; 34.1%), β‐hemolysis streptococcus spp. (18/120; 15%), Streptococcus aureus (17/120; 14.1%) and Escherichia coli (11/120; 9.1%), respectively. Other isolated bacteria were Streptococcus spp., Escherichia coli and Corynebacterium spp. Of the total of 120 cultures, 10 (8.3%) were negative in all the seasons. No negative culture was observed in summer, while 8 cultures were negative in autumn and winter. Conclusions: Results of this study revealed gram‐positive bacteria as the most dominant microorganisms of the normal ocular surface of healthy cats in all seasons. This is while no gram‐negative bacteria were isolated during autumn and winter. None.

Comparison of schirmer tear test, phenol red thread test and endodontic absorbent paper point tear test for measurement of the aqueous tear film fraction in healthy cats and their correlation to stress level

S Rajotte, T Villar, KM Smith‐Fleming and BC Martins

Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign, IL, USA

Purpose: To compare measurements of the aqueous tear film fraction in healthy cats obtained using different quantitative tear tests while exploring the impact of stress level. Methods: A prospective, randomized, cross‐over study was performed using twenty‐three healthy adult cats with normal ophthalmic exams. Schirmer tear tests (STT1) and phenol red thread test (PRT) were performed via standard technique in both eyes. Endodontic absorbent paper point tests (PPTT) were conducted for 15 s in both eyes. All tests were performed at 2 h intervals on the same day. Stress level was quantified prior to and during each individual test using a published modified Demeanor Score. Tear production values and stress level scores were compared using One‐Way ANOVA. The correlation between tear tests and stress score was verified by Scatterplot and Pearson's correlation coefficient. Results: Mean STT1 (mm/min) was 12.69 ± 4.21 OD and 14.96 ± 3.56 OS. Mean PRT (mm/15 s) was 26.39 ± 5.6 OD and 26.52 ± 4.9 OS. Mean PPTT (mm/15”) was 14.65 ± 5.2 OD and 11.95 ± 2.7 OS. There was no significant difference in stress score among tear tests (P = 0.99). A weak negative correlation was noted between STT1 and stress score in both eyes (r = −0.4) and between PRT and stress score OS (r = −26). No correlation was noted between PRT OD and stress score or between PPTT and stress score in both eyes. Conclusions: Stress level may influence STT1 and PRTT results, but does not appear to influence PPT results. None.

Pleomorphic iridociliary adenocarcinoma with extraocular extrusion in a dog

S Rajotte,¹ RE Hamor,² P Roady¹ and BC Martins¹

¹College of Veterinary Medicine, University of Illinois, Urbana‐Champaign, IL, USA; ²College of Veterinary Medicine, University of Florida, Gainesville, FL, USA

Purpose: To report a case of pleomorphic iridociliary adenocarcinoma with extraocular extrusion in a dog. Methods: A 13‐year‐old Golden Retriever was referred to the University of Illinois Ophthalmology Service for evaluation of a corneal mass that was progressing for over a year. Complete ophthalmic examination and systemic workup were performed. The globe was non‐visual and painful, as for was enucleated and submitted for histopathology. Results: Examination revealed a multilobular, pink, raised mass extruding from inside the eye through the cornea. Exteriorized area was 10 mm in diameter and 5 mm in elevation from the cornea. The remainder of the globe could not be visualized. Complete staging did not reveal any macroscopic metastasis. Gross examination of the globe revealed an expanding, unencapsulated, poorly circumscribed and invasive neoplasm effacing the iris, anterior and posterior chamber, cornea, sclera, and choroid with exteriorization through the cornea. Neoplastic cells originated from the ciliary body and were arranged in tubules, cords, nests and clusters. Neoplastic cells were cuboidal to polygonal, with marked anisocytosis and anisokaryosis, with 150 mitotic figures in ten high power fields. Neoplastic cells were found in blood vessels and areas of necrosis were present. The mass was positive for cytokeratin and vimentin. The neoplasm was diagnosed as pleomorphic adenocarcinoma of the ciliary body with extraocular extrusion. Conclusions: To the authors’ knowledge, this is the first report of adenocarcinoma of the ciliary body with exteriorization through the cornea. This should be added to the list of differentials for an apparent corneal mass. None.

Ocular manifestations of Cryptococcus gattii in a dog in Oregon: case report

AJ Rogen, PG Scherlie and MG Taylor

VCA Northwest Veterinary Specialists, Ophthalmology Division, Clackamas, OR, USA

Purpose: To describe the ocular clinical signs and the progress over 3 months of a dog with retrobulbar cryptococcosis, which was confirmed as Cryptococcus gattii via retrobulbar aspirate culture. Methods: A 2‐year‐old intact male Doberman Pinscher – mix breed dog was presented with exophthalmos of the right eye initially unresponsive to oral antibiotics (marbofloxacin and amoxicillin with clavulanic‐acid) and anti‐inflammatories (carprofen). A serum latex agglutination antigen detection (LAT) titer and bloodwork was suggested for further investigation. Results: The patient had an unremarkable complete blood count, serum chemistry, and urinalysis. The patient tested positive for cryptococcosis with the LAT titer. Retrobulbar aspirate showed numerous broad‐base budding yeast cells consistent with Cryptococcus organisms. Fungal culture from the retrobulbar aspirate using L‐canavanine‐glycine‐bromothymol blue (CGB) differentiating medium confirmed Cryptococcus gattii infection. Treatment with fluconazole (4 mg/kg/BID/PO) was prescribed. The patient's exophthalmos worsened over a 1 month period. Exophthalmos improved following transition to oral itraconazole (8 mg/kg/BID/PO) and terbinafine (10 mg/kg/QD/PO). Treatment is currently ongoing. Conclusions: Cryptococcus gattii should be considered as a differential diagnosis in veterinary patients with a travel history to the Pacific Northwest presenting with exophthalmos. Azole anti‐fungal resistance is becoming more prevalent in Pacific Northwest Cryptococcus gattii. To the author's knowledge, this is the first report of Cryptococcus gattii diagnosed via fungal culture from a retrobulbar aspirate. None.

Gonioscopy, SD‐OCT, high‐resolution ultrasound, and Pentacam^® HR imaging to develop a detailed iridocorneal angle assessment in rabbits

MC Rollert, KS Freeman, AM Cleymaet, SL Pederson, AC Morphet, FJ Olea‐Popelka, SC Dinger, LC LiPuma and MS Johnston

Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA

Purpose: Iridocorneal angle (ICA) narrowing is a known risk factor for primary glaucoma in multiple species, but is poorly described in companion rabbits. The aim of this study was to develop an ICA grading scheme for companion rabbits to facilitate early glaucoma predisposition diagnosis. Methods: Twenty healthy rabbits of varying breeds and ages received complete ophthalmic examinations, including gonioscopy, followed by imaging of the ICA using spectral domain optical coherence tomography (SD‐OCT), Scheimpflug imaging (Pentacam^® HR), and high resolution ultrasound (HRUS). Iridocorneal angle opening distance (AOD) and angle recess area (ARA) were measured and assessed for agreement using a Bland‐Altman analysis. A 5‐stage gonioscopy grading scheme was created and a Spearman‐rank test was used to assess for correlation between gonioscopy scores and ICA measurements. Differences amongst age and gender were analyzed with a non‐parametric ANOVA and a Wilcoxon rank‐sum test, respectively. Results: Analysis revealed AOD medians of 0.28 mm for SD‐OCT [95% CI 0.24–0.31], 0.20 mm for Pentacam^® HR [95% CI 0.179–0.21], and 0.25 mm for HRUS [95% CI 0.22–0.28]. The median ARA was 0.14 mm² for SD‐OCT [95% CI 0.1173–0.1627], 0.09 mm² for Pentacam^® HR [95% CI 0.082–0.100], and 0.06 mm² for HRUS [95% CI 0.046–0.054]. The association between gonioscopy score and SD‐OCT ARA was significant (P < 0.05), and there was a significant difference (P < 0.001) between imaging modalities for both ARA and AOD. Conclusions: Gonioscopy grading scheme correlated best with SD‐OCT ARA. We therefore recommend SD‐OCT as the preferred non‐contact method for evaluating rabbit ICA. Each imaging device should not be used interchangeably. Supported by 2016 Young Investigator Grant Program, Center for Companion Animal Studies, Colorado State University. None.

The effects of demecarium bromide and latanoprost on intraocular pressure and iridocorneal angle parameters of rabbits

MC Rollert, KS Freeman, SL Pederson, AM Cleymaet, AC Morphet, FJ Olea‐Popelka, SC Dinger, LC LiPuma and MS Johnston

Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA

Purpose: Onset of primary glaucoma in companion rabbits is often insidious and late‐stage diagnosis can make glaucoma therapy less efficacious. This study aimed to determine the effects on intraocular pressure (IOP) and iridocorneal angle (ICA) measurements of two glaucoma therapies, 0.125% demecarium bromide (demecarium) and 0.005% lanatoprost in rabbits. Methods: Twenty rabbits of varying breeds and ages received a complete ophthalmic examination, including rebound tonometry and gonioscopy grading. ICA imaging including angle opening distance (AOD) and angle recess area (ARA) measurements was performed using spectral domain optical coherence tomography (SD‐OCT), high resolution ultrasound (HRUS), and Scheimpflug imaging (Pentacam^®‐HR). Demecarium was applied to one eye and latanoprost to the opposite eye. Each eye was re‐evaluated 1 h later with tonometry, imaging, and gonioscopy. Pre‐ and post‐treatment values were compared with a paired T‐Test for IOP, ARA, and AOD and with a Wilcoxon rank‐sum test for gonioscopy grade. Results: IOP significantly increased with demecarium (mean difference = 11.3 mmHg [95% CI 7.1–15.5]) and significantly decreased with latanoprost (mean difference = 2.1 mmHg [95% CI 3.1–1.1]). Demecarium caused a significant decrease in gonioscopy grade, ARA, and AOD when measured via SD‐OCT and Pentacam^®‐HR (P < 0.05). Latanoprost caused a significant increase in gonioscopy grade, ARA, and AOD when measured via SD‐OCT (P < 0.05). Conclusions: Demecarium increased IOP and decreased ICA parameters; therefore its use in rabbits is not recommended. Latanoprost decreased IOP and increased ICA parameters and can be considered a possible therapy for rabbit glaucoma. Supported by 2016 Young Investigator Grant Program, Center for Companion Animal Studies, Colorado State University. None.

Correlation between spectral domain optical coherence tomography and histologic evaluation of the retina of blue‐fronted parrots (Amazona aestiva)

RA Pecora,¹ SS Watanabe,² AC Santos,³ D Otsuki,⁴ PSM Barros¹ and AMV Safatle¹

¹Laboratory of Experimental Comparative Ophthalmology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil; ²School of Medicine, Federal University of São Paulo, São Paulo, Brazil; ³Laboratory of Morphological Study of Reproduction Biology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil; ⁴LIM‐08, School of Medicine, University of São Paulo, São Paulo, Brazil

Purpose: To perform standardized spectral domain optical coherence tomography (SD‐OCT) of the retina of healthy, adult, blue‐fronted‐parrots (Amazona aestiva) and compare the measurements to those taken on histologic evaluation Methods: Forty‐three parrots had their pupils dilated with topical instillation of rocuronium (5 mg/ml). They were anesthetized with midazolam IM (0.5 mg/ml) and propofol IV (5 mg/ml), and then examined by SD‐OCT (Heidelberg Engineering Spectralis OCT; Heidelberg Engineering, CA, USA). Measurements of the total retina (RT), neurosensory retina (RN) and the complex of ganglion cells (CCG) consisting of thenerve fiber layer, ganglion cell layer, external plexiform layer were acquired 2 mm from the pecten towards the fovea. Six parrots were euthanized, their eyes enucleated, and sent for retinal analysis and measurement using the fluorescence microscope BX61VS (Research System Microscope Olympus BX61VS; Olympus Corporation, Tokyo, Japan) and VS‐ASW^® software. Results: SD‐OCT measurements were 305.1 ± 17.25 μm, 279.4 ± 17.48 μm and 138.6 ± 20.72 μm for RT, RN and CCG respectively. Thehistologic measurements were 260.3 ± 69.88 μm, 238.2 ± 60.53 μm and 129.3 ± 25.59 μm for RT, RN and CCG. The correlation coefficient between all the measurements obtained by OCT and by microscopy was high (r = 0.86, P < 0.0001),. When each was analyzed separately, CCG showed a better correlation (r = 0.99, P < 0.0001). Conclusion: SD‐OCT was an excellent instrument for the in vivo evaluation of the blue‐fronted parrot retina, providing detailed and accurate images of the posterior segment when compared to histologic evaluation. Support: FAPESP grant n°2011/24039‐8.

Post‐treatment effects of two steroidal anti‐inflammatory ophthalmic drugs on protein concentration in the secondary aqueous humor of dogs

K Sato,¹ K Kanai,¹ K Iwasaki,¹ T Kagawa,¹ M Ozaki,¹ N Nagai,² Y Yamashita,¹ S Chikazawa¹ and H Hoshi¹

¹Department of Small Animal Internal Medicine II, School of Veterinary Medicine, University of Kitasato, Tokyo, Japan; ²Faculty of Pharmacy, Kindai University, Higashi‐osaka, Japan

Purpose: To investigate the post‐treatment effects of two steroidal anti‐inflammatory ophthalmic drugs on the breakdown of blood–aqueous barrier (BAB) by paracentesis in dogs. Methods: 24 ocular‐normal dogs were equally divided into one control and two treatment groups (n = 8/group). Non‐leaking anterior chamber paracentesis (450 μl) was performed in one eye of each dog. Dogs in the control group received no medication and those in the treatment groups received a topical anti‐inflammatory medication [difluprednate ophthalmic emulsion (DFBA), 0.05% or betamethasone sodium phosphate ophthalmic solution (BMZ), 0.1%] at 0, 15, 30 and 45 min after initial paracentesis in the treated eyes. The secondary aqueous humor (AH) was collected 60 min after the initial paracentesis. Protein concentration in AH was determined using the bicinchoninic acid assay. Mean values of the control and treatment groups were compared using ANOVA followed by Tukey's post‐hoc test. Results: The treatment with both drugs, particularly DFBA (P < 0.05), reduced protein concentration in the secondary AH. With both drugs, there was no significant difference in the intraocular pressure and pupil diameter from the control group at any time point. Conclusion: Post‐treatment effects of DFBA were more effective than those of BMZ for reducing aqueous protein content in dogs with paracentesis‐induced BAB breakdown. These results indicated that DFBA may be an appropriate treatment in an early stage of acute anterior uveitis caused by intraocular surgery in dogs. Supported by the Sasakawa Scientific Research Grant from The Japan Science Society (29‐439). None.

Detection of papillomavirus DNA in canine lobular orbital adenoma

EA Schaefer, S Chu, JN Bryan, JW Pearce and BK Flesner

Department of Veterinary Medicine and Surgery College of Veterinary Medicine, University of Missouri, Columbia, MI, USA

Purpose: Our study aims are (1) to evaluate phenotypically normal canine conjunctival and orbital tissue for the presence of papillomavirus DNA and (2) determine if papillomavirus DNA is present in tissue from canine lobular orbital adenomas. Methods: Thirty‐three formalin‐fixed paraffin embedded (FFPE) canine lobular orbital adenoma tissue samples were obtained from the Comparative Ocular Pathology Lab of Wisconsin. In addition, a fresh ex vivo tumor sample was collected for analysis. Excisional biopsies of conjunctival and orbital tissue of ten phenotypically normal dogs were collected. Four FFPE tissue samples previously confirmed to be positive for papillomavirus DNA served as positive controls. Non‐template samples served as negative controls. Genomic DNA was extracted from all samples and evaluated via a non‐species specific papillomavirus polymerase chain reaction (PCR). Results: Polymerase chain reaction results verified negative and positive controls. Papillomavirus DNA has not been detected in fresh conjunctival and orbital tissue of phenotypically normal dogs or in samples of fresh or FFPE canine lobular orbital adenoma tissue. Conclusions: Papilloma viruses do not appear to be associated with the development of canine lobular orbital adenoma. Further research is needed to evaluate if other viruses play a role in the pathogenesis of canine lobular orbital adenomas. Supported by the ACVO Vision for Animals Foundation Grant VAF2017‐01 and in part by the University of Missouri Phi Zeta Honor chapter. None.

Investigation of post‐sterilization hyphema in shelter cats

AP Schenk,¹ CA Beatty,² AM McGrath,² SA Robertson¹ and AM Komáromy¹

¹College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; ²Capital Area Humane Society, Lansing, MI, USA

Purpose: Formally confirm and characterize cases of hyphema in shelter cats following sterilization surgery. Methods: In part 1, a short survey regarding past experiences was sent to veterinarians in shelters, as well as High‐Quality High‐Volume Spay‐Neuter (HQHVSN) practices throughout the United States, and 20 responses were collected. In part 2, 195 cats of ages 2–36 months (112 males and 83 females) to be spayed/neutered at the Capital Area Humane Society (CAHS) underwent complete ophthalmic exams, including rebound tonometry, before and after surgery. All patients received buprenorphine (0.006 mg/kg SQ) and acepromazine (0.05 mg/kg SQ) for premedication. Male kittens under 4.4 lbs (2 kgs) received tiletamine/zolazepam (Telazol^®; 6.6 mg/kg IM; N = 93). Female kittens and adult cats received ketamine/midazolam (5.5 and 0.275 mg/kg respectively IV; N = 102) for induction. Results: Of the 20 survey responses collected in part 1, 9 reported having witnessed post‐sterilization hyphema at some point during their career. Of these 9, 7 had anesthetic protocols involving Telazol^® as an induction agent. In part 2, one cat out of 195 examined (˜0.5%) developed bilateral anterior uveitis and hyphema within 1 h following surgery with Telazol^® protocol. The clinical signs completely resolved within 24 h. Conclusions: Transient hyphema following sterilization surgery is a well‐recognized complication of sterilization surgery in shelter cats especially with the use of Telazol^®. The etiology of this observation remains unknown, and there appears to be no lasting ocular damage. Funding provided by the Michigan State University Graduate Office Fellowship. None.

An unusual case of feline acute corneal hydrops: atypical disease presentation and possible in vivo detection of descemet's membrane detachment in the cat's unaffected eye

BN Schlesener, EM Scott and LV Vallone

College of Veterinary Medicine, Texas A&M University, College Station, TX, USA

Purpose: To describe a case of unilateral FACH in which suspected DM detachment was detected in vivo by AS‐OCT in the cat's contralateral, clinically healthy eye. Methods: A 1‐year‐old, female spayed, domestic shorthair cat presented for blepharospasm of the right eye. Ophthalmic examination was performed including fluorescein stain, slit‐lamp biomicroscopy and binocular indirect ophthalmoscopy. The right eye displayed a geographic corneal ulcer with marked edema and a gross distortion of the corneal profile consistent with FACH. Corneal cytology and bacterial culture were obtained. Slit‐lamp biomicroscopy of the left eye demonstrated a focal endothelial opacity within the central cornea. Surgical management of the right eye included a bridge conjunctival graft, third eyelid flap, and temporary tarsorrhaphy. At a follow up examination 24 days after the surgery, AS‐OCT was performed on both eyes. Results: Cytology and bacterial culture did not demonstrate the presence of microorganisms. The patient regained comfort and was free of corneal edema in the right eye. The left eye remained unchanged at follow up examinations. Compete evaluation of the right cornea with AS‐OCT was difficult due to the presence of conjunctival tissue over the central cornea, however the central cornea of the left eye displayed a focal separation of the corneal endothelium and DM from the overlying stroma with subtle corneal edema. The patient was lost to further follow up. Conclusions: These AS‐OCT findings are similar to acute corneal hydrops (ACH) in humans and may represent a potential etiology for FACH in the case presented here. None.

Reliability of intraocular pressure measured by a Tonovet^® rebound tonometer in normal pigeon eyes

JG Lim, S Kang, S Park, EJ Park, TJ Nam, SW Jeong and K Seo

Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea

Purpose: To evaluate the applicability of a TonoVet^® rebound tonometer in pigeon eyes and to establish normal reference intraocular pressure (IOP) values of healthy pigeons. Methods: Twenty eyes of euthanized pigeons were used for the calibration of TonoVet^® and 48 eyes of 24 adult pigeons for the reference IOP. First, IOP of pigeon eyes ex vivo were measured using ‘d’ and ‘p’ modes of the TonoVet^® and compared with manometric IOP values from 5 to 80 mmHg. Then, to establish normal reference values, IOP was measured from clinically normal pigeons in vivo. Results: Both ‘d’ and ‘p’ modes of the TonoVet^® showed a strong linear correlation with the manometric IOP (r² = 0.996 and 0.991, respectively). The obtained regression formulas were y = 0.431x1 + 2.154 and y = 0.330x2–0.673, respectively (x1, ‘d’ mode of TonoVet^®; x2, ‘p’ mode of TonoVet^®; y, manometric IOP). The ‘d’ and ‘p’ modes steadily underestimated the actual IOP by approximately 1/2 and 1/3, respectively. Therefore, the formula obtained through ‘d’ mode was applied to obtain reference values. The calibrated IOP of normal pigeon eyes was 19.5 ± 4.4 mmHg. Conclusions: The actual IOP could be calculated using the presented formula. Considering the limitations of ‘p’ mode, it would be more appropriate to use ‘d’ mode. Therefore, the TonoVet^® rebound tonometry under ‘d’ mode is a reliable method for measuring IOP in pigeons. None.

Intraocular melanocytic tumors in young dogs: clinicopathologic features and breed prevalence

GC Shaw, RR Dubielzig and LBC Teixeira

Department of Pathobiological Sciences, Comparative Ocular Pathology Laboratory of Wisconsin, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA

Purpose: To characterize intraocular melanocytic tumors in dogs less than 2 years of age in the COPLOW collection. Methods: The COPLOW database was mined for globes with intraocular melanocytic tumors from dogs less than 2 years of age. Cases were summarized and the histopathology of each case was reviewed. The number of affected dogs in various breeds was evaluated statistically. Results: From a total of 1686 dogs less than 2 years of age in the COPLOW database 32 cases of intraocular melanocytic tumors were identified. The median age of affected animals was 12 months (range 2–23 months). Labrador retrievers (12/32) and German shepherds (3/32) were the most prevalent breeds, but 14 other breeds were represented. In our cohort, intraocular melanocytic tumors were significantly more prevalent in Labrador retrievers than other breeds (odds ratio 4.2, 95% CI [2.0, 8.8], P < 0.0001). Based on the presence of 4 or more mitotic figures in ten 400× fields, the tumors were divided into benign (melanocytoma) or malignant (melanoma). There were 10 melanocytomas and 2 malignant melanomas within the population of Labrador retrievers. All tumors of non‐Labrador retriever breeds were melanocytomas. Tumors affected the anterior uvea in 31/32 cases. The remaining case was from a Labrador and was classified as a choroidal melanocytoma. Conclusions: Though rare, intraocular melanocytic neoplasms can develop in young dogs and are significantly more prevalent in young Labrador retrievers than in young dogs from other breeds. The cause of the Labrador breed prevalence and the pathogenesis of these early developing tumors yet unknown. None.

Comparison of retinoid amino acid sequences across 11 species

CK Sheridan

College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA

Purpose: Loss of function mutations described in humans and veterinary species that prevent recycling of the visual chromophore rhodopsin result in retinal degeneration and vision loss. Gene therapy restoring visual function in RPE65 mutants has been successfully explored in mice, dogs, and monkeys. In this study, amino acid sequences of proteins involved in retinoid cycling across vertebrates were compared to determine the degree of conservation. Highly conserved sequences indicate importance for basic cellular function and may be good candidates for models of disease or gene therapy. Methods: Vertebrates were surveyed for sequence homology with the human proteins RPE65, CRBP1, CRALBP, RDH5, RDH12, LRAT, and IRBP. A mixed population of 11 species important to veterinary medicine was then selected for in‐depth analyses. Sequence similarity was examined based on substitution matrices for scoring alignments between evolutionarily divergent sequences and substitution patterns based on similar properties. Results: Across vertebrates, RPE65 was the most conserved protein (˜90% identical) and exhibited the least variation. LRAT and IRBP were the least conserved (˜70% identical) and exhibited the most variation. In the mixed population of 11 species, the order of homology was found to be RPE65 (96% identity), CRBP1 (93%), CRALBP (90%), RDH12 (88%), RDH5 (87%), LRAT (84%), and IRBP (81%). Amino acid substitutions increased the percent similarity and decreased the variation compared with the corresponding percent identical values. Conclusions: RPE65 and CRBP1 appear more highly conserved than other retinoid cycling proteins. None.

Evaluation of microbial contamination of canine plasma eye drops using two types of eyedropper bottles

RA Strauss,¹ RA Allbaugh,¹ U Genschel² and G Ben‐Shlomo¹

¹Department of Veterinary Clinical Sciences, Iowa State University, Ames, IA, USA; ²Department of Statistics, Iowa State University, Ames, IA, USA

Purpose: To investigate microbial contamination of canine plasma eye drops when used clinically and to compare the effect of two different eyedropper bottles on contamination rate. Methods: Forty‐six bottles containing plasma were dispensed for use on 42 dogs with ulcerative keratitis. Of these, 23 were standard eyedropper bottles and 23 were Novelia^® bottles designed to prevent contamination. After use for up to two weeks, samples for bacterial culture were obtained from a drop of plasma, the bottle tip, the plasma inside the bottle, and the corneal surface. Fungal culture was performed from a drop of plasma. Results: The overall microbial contamination rate was 17.4% (8/46 bottles); however, only one bottle had growth from the plasma inside. There was a lower contamination rate with Novelia^® bottles (3/23 = 13.0%) compared to standard bottles (5/23 = 21.7%), but this was not statistically significant (P = 0.57). There was also a nonsignificant increase in contamination rate with bottles used greater than 7 days (7/35 = 20.0%) compared to less than or equal to 7 days (1/11 = 9.1%) (P = 0.62), and greater than 4 times daily (4/17 = 23.5%) compared to 4 times daily or less (4/29 = 13.8%) (P = 0.49). Three corneal samples (6.5%) had bacterial growth, but none matched contamination from the bottles. Conclusion: Novelia bottles may decrease contamination of plasma eye drops used clinically. However, while microbial contamination of plasma bottles was seen in this study, no clinically relevant complications were observed. This study supports safe use of plasma eye drops for up to two weeks. Supported by Iowa State VCS Research Incentive Grant. None.

Corneal squamous cell carcinoma and actinic keratosis: a retrospective case series with dogs living in a high ultraviolet index region in Brazil

VRP Magri,¹ AL Teixeira,² V Voget,² LB Cossi,³ SSS Lima⁴ and AL Andrade⁴

¹Department of Ophthalmology – University Center of Rio Preto, Rio Preto, Brazil; ²Department of Ophthalmology and Visual Science – Provet, São Paulo, Brazil; ³Department of Ophthalmology – PetVisão, São José do Rio Preto, Brazil; ⁴Paulista State University – Júlio de Mesquita Filho, São Paulo, Brazil

Purpose: Squamous cell carcinoma (SCC) is rare in dogs and there are few published case reports. This study reports a case series of 6 dogs with SCC and 1 dog with actinic keratosis (AK) treated in São José do Rio Preto‐SP, Brazil, from 2009 to 2017. Methods: A retrospective analysis of 6 dogs with corneal SCC and 1 dog with AK. Six dogs were treated at Veterinary Hospital “Dr. Halim Atique” in University Center of Rio Preto – UNIRP, and 1 dog was treated at “Pet Visão” – a veterinary clinic. Results: There were 5 females and 2 males with ages ranging between 7 and 11 years old, averaging 9.5 years old. There were 2 Boxers, 1 English Bulldog, 1 Weimaraner, 1 Spitz and 1 mixed‐breed dog with SCC and 1 Boxer with AK. Superficial keratectomies were performed in 6 dogs that had only corneal lesions and an exenteration was conducted in the seventh dog that had corneal, limbal, conjunctival and nictitans membrane involvement. Conclusion: Given that corneal SCC and AK are rarely reported in dogs, this case series observed in the same geographic location in a relatively short timespan suggest that some special factors may be contributing to the development of these neoplasic and pre‐neoplasic lesions. According to the literature, exposure to ultraviolet light could increase the risk of developing SCC or AK. Since São José do Rio Preto has a high incidence of UV radiation, we especulate that this environmental factor might be linked to the cases reported.

Keywords: Carcinoma, keratectomies

Flicker fusion frequency of white‐tailed deer and management implications for deer vehicle collisions

TM Treen,¹ EM Watson,² BS Cohen,² DA Osborn,² M Barletta,³ K Mitchell,¹ KE Myrna¹ and KV Miller²

¹Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, USA; ³Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA, USA; ²Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA

Purpose: To measure the critical flicker fusion point (CFF) of white‐tailed deer. Methods: 7 ophthalmically normal, captive raised white‐tailed deer were anesthetized with xylazine 2 mg/kg combined with either ketamine 6 mg/kg or telazol 4 mg/kg. A custom electroretinogram (ERG) was performed measuring responses at frequencies of 0.5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90 and 100 hz at light intensities of 100–10,000 mcd/m² for the scotopic study and 2500–100000 mcd/m² for the photopic study. Each waveform peak‐to‐trough amplitude was measured and the average at each stimulus frequency was calculated. The average peak‐to‐trough measurements (uV) were plotted against the stimulus frequency (hz) and a least means linear regression line was fit to the data. The CFF was determined at the x intercept with the x‐axis representing a background noise amplitude of zero. CFF at each intensity was averaged. Results: CFF in the scotopic study ranges from 41 ± 4.7 hz ‐77.5 ± 21 hz with each doubling of light intensity resulting in a 2–7 hz increase in the CFF point. The photopic study showed a CFF between 98 ± 4 hz and 107 ± 9.8 hz. Conclusion: Under scotopic conditions, the CFF point in white‐tailed deer is approximately 50 hz whereas under photopic conditions the CFF point is approximately 100 hz. This knowledge will allow us to further investigate the application for white‐tailed deer management. For future studies, we hope to determine if developing a headlight below the CFF of deer, yet higher than the CFF of humans would decrease deer vehicle collisions. None.

Bacterial characterization and antimicrobial susceptibility of conjunctival flora in healthy dogs in Ibagué, Colombia

DY Trujillo¹ and MP Sanchez¹

¹College of Veterinary Medicine and Animal Science, Colombian Cooperative University, Ibagué, Colombia

Purpose: Identify bacterial conjunctival microflora and its susceptibility to antibiotics in healthy canines in Ibagué, Colombia. Methods: The study included 30 adult clinically normal dogs without ophthalmic alterations. Samples were obtained by passing a sterile swab moistened in sterile saline across the lower conjunctival sac of the right eye. The swabs were transported on Amies agar gel, inoculated in blood and MacConkey agars and incubated at 37°C under aerobic conditions for 24–48 h. Bacterial colonies were identified by classic methods including Gram staining, colony morphology and biochemical tests for identification (BBL crystal identification systems). Antimicrobial susceptibility was determined by Kirby‐Bauer disk diffusion technique. The antimicrobial agents used were: tobramycin (10 μg), ciprofloxacin (5 μg), sulphamethoxazole‐trimethoprim (25 μg), gentamicin (10 μg) and tetracycline (30 μg). The study was conducted utilizing descriptive variable analysis. Results: Bacteria were isolated of 14 (46.6%) of 30 normal samples. Gram positive bacteria (85.70%) were isolated more frequently than gram negative bacteria (14.30%). The isolated bacteria were: coagulase‐negative Staphylococci (CoNS) (28.57%), Staphylococcus intermedius (7.14%), Streptococcus intermedius (14.28%), Corynebacterium spp (14.28%), Enterobacter cloacae (7.14%), Actynomices spp (7.14%), Corynebacterium striatum (7.14%), Bacillus cereus (7.14%), Acinetobacter baumannii (7.14%). The profile of resistance‐sensibility were: 11.20–88% to ciprofloxacin, 44.5–55% to tetracycline, 22–78% to gentamicin and 33–67% to sulphamethoxazole‐trimethoprim and tobramycin. Conclusions: To the author's knowledge, this is the first study of conjunctival microflora characterization of Colombian dogs. Coagulase‐negative Staphylococci was the most frequent conjunctival bacterial genera. Conjunctival flora of Ibagué's dogs were highly sensitive to ciprofloxacin and remarkably resistant to tetracycline. Support: Conadi. None.

Conjuntival flora of normal thoroughbred horses in Rio de Janeiro

JB Vieira,^1,2 A Kuner,² MS Silva,¹ TRM Carvalho¹ and LH Souza¹

¹Jockey Club Brasileiro, Gávea, Rio de Janeiro, Brazil; ²Vet Eyes, Rio de Janeiro, Brazil

Purpose: To report and compare the prevalence of aerobic bacterial flora on the conjunctival fornix of normal eyes of horses stabled at Jockey club Brasileiro and in a training facility in Rio de Janeiro. Methods: The investigation included 34 healthy race horses. 27 animals were stabled inside the racetrack and 7 at the training center 120 km from Jockey Club Brasileiro. Each animal had the ventral conjunctival fornix of right eye swabbed with sterile culturettes. Aerobic cultures were sent to the laboratory the same day. Results: Of 34 normal equine eyes, 21 were positive for Staphyloccus spp only (61.76%), the next most frequently isolated alone was Proteus spp. (17.65%) in 6 cases, one single sample was positive for Streptococcus spp (2.94%). 6 horses presented mixed bacterial flora. The most common findings were Staphyloccus spp/ Corynebacterium spp (8.83%), Staphyloccus spp/ Pseudomonas spp. (2.94%), Staphyloccus spp/ Klebsiella spp (2.94%) and Klebsiella spp/ Corynebacterium spp (2.94%). Conclusions: Among the Thoroughbred horses stabled inside Jockey Club Brasileiro Staphyloccus spp was the most frequently isolated organism, among the animals at the Training center. Proteus spp. was the most common aerobic bacteria. The horses that presented mixed flora findings had a history of recent arrival from another state with significant climatic difference. The results suggest that bacterial flora might be regionalized.

An overview of procollagen amino‐propeptide type I (PINP) and procollagen amino‐propeptide type III (PIIINP) protein expression in the normal and diseased canine corneal stroma

YN Vu,^1,2 N Hamilton,³ DJ Whitworth,¹ CR Green⁴ and JD Wright¹

¹School of Veterinary Science, The University of Queensland, Brisbane, Qld, USA; ²Nong Lam University, Ho Chi Minh City, Vietnam; ³Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, USA; ⁴Department of Ophthalmology, The University of Auckland, Auckland, New Zealand

Purpose: Disruption of the corneal stroma by disease or injury often causes permanent scarring or blindness. One hypothesis is that the normal parallel organisation of collagen type I fibrils is disrupted by the increased synthesis of disorganised collagen type III fibrils that occurs during the initial reparative process following injury and disease. The aim of this study was to characterise the morphologic and immunohistochemical features of type I and type III procollagen protein synthesis in the normal and diseased canine corneal stroma. Methods: Eighteen normal and four abnormal canine corneas were examined. Sagittal corneal sections were stained for histological examination with H&E and PAS, and immunohistochemically with anti‐PINP and anti‐PIIINP antibodies. PINP and PIIINP protein distribution was identified using confocal laser scanning microscopy; and quantified as the number ratio (GJ number/keratocyte) and average dot volume per nucleus (GJ volume in pixels/keratocyte) using ImageJ. Results: PINP protein was expressed uniformly at a constant but low level along collagen fibril lamellae throughout all normal canine stroma whereas PIIINP protein was expressed sparsely or not detectably. In the diseased stroma, PINP and PIIINP protein expression was considerable increased in both distribution and volume. Distribution of PIIINP, in particular, was typically disorganised. Conclusions: This study provides the arrangement and degree of expression of PINP and PIIINP protein in normal and diseased canine corneal stroma. PIIINP protein synthesis was increased during injury; therefore, targeting collagen type III gene and protein expression may reduce scarring after corneal injury and disease. Supported by the Canine Research Foundation, the John and Mary Kibble Trust and The University of Queensland, Australia. Commercial Relationships: YN Vu, None; N Hamilton, None; DJ Whitworth, None; CR Green, None; and JD Wright, None.

Modified evisceration and intrascleral prosthesis in a Dusky Gopher Frog, Lithobates sevosus, due to corneal perforation and iris prolapse

AE Zibura,¹ MdL Henriksen,^1,2 C Baldo,³ H Shipley,³ B Ericksen⁴ and M Trent^4,5

¹Comparative Ophthalmology, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA; ²Comparative Ophthalmology, College of Veterinary Medicine, Colorado State University, Fort Collins, CO, USA; ³Anesthesiology, College of Veterinary Medicine, University of Minnesota, Minnesota; ⁴Como Park Zoo and Conservatory, Saint Paul, MN, USA; ⁵Large Animal Surgery, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA

Purpose: The aim of this study was to evaluate the feasibility of a modified evisceration technique for treatment of a corneal perforation in a Dusky Gopher Frog, Lithobates sevosus. Methods: A mature female Dusky Gopher frog, Lithobates sevosus, an endangered species, presented to the University of Minnesota Veterinary Medical Center for evaluation of right‐sided traumatic corneal perforation of one‐day duration. Results: Modified ocular evisceration was performed, removing the cornea and all intraocular contents while preserving the integrity of the cartilaginous sclera. This technique was selected to maintain normal swallowing capability through preservation of the globe's role in food propulsion. A 5 mm diameter silicone intrascleral prosthesis was implanted, and the defect was closed via permanent tarsorraphy, suturing the nictitating membrane to the immobile upper lid. Anesthetic recovery was uneventful. Unfortunately, the frog died 24 h post‐operatively. The official necropsy report implicates unrelated underlying renal disease as the ultimate cause of death. Conclusion: This case report demonstrates the potential to utilize a modified evisceration technique for treatment of corneal perforation in frogs. Adequate depth of anesthesia was obtained and no adverse anesthetic effects were noted in the peri‐operative period. Long‐term follow‐up was not available. None.