An Atypical Presentation of Propionibacterium Acnes Endophthalmitis Following Cataract Surgery

Abstract

Purpose:

To describe a case with an unusual presentation of Propionibacterium acnes (P acnes) with ultimately a good visual outcome.

Methods:

A case report with review of approaches to P acnes endophthalmitis.

Results:

We describe a patient with an unusual presentation of P acnes of panuveitis with white, circular preretinal lesions without intracapsular deposits. Diagnosis was made from cultures from pars plana vitrectomy. Eventually, she was definitively managed with capsulectomy, repositioning of her intraocular lens via sutureless intrascleral fixation, and intravitreal vancomycin injection.

Conclusion:

This is a report of P acnes endophthalmitis presenting with discrete preretinal lesions where surgical and medical management lead to a complete resolution of uveitis and symptoms after a 3-year follow up where the patient’s final visual acuity was Snellen 20/20 OU.

Introduction

Postoperative endophthalmitis is an uncommon but potentially visually devastating complication of any intraocular surgery, occurring in 0.07% to 0.13% of cases worldwide. ¹ Propionibacterium acnes (P acnes), a gram-positive anaerobic bacillus, is the most commonly identified cause of chronic postoperative endophthalmitis—defined as a delayed intraocular infection occurring 6 weeks or more after intraocular surgery—and has been estimated to occur in 0.017% of all cataract surgical procedures. ² The usual clinical findings of P acnes include granulomatous uveitis, hypopyon, mild vitritis, and a white intracapsular plaque. ³ Despite being more often associated with delayed-onset infections, P acnes can also cause acute endophthalmitis. ¹

We describe a case of late-onset, postoperative P acnes endophthalmitis presenting with multiple white, discrete, small preretinal inflammatory lesions. The endophthalmitis recurred 5 weeks later with the classic intracapsular plaque, requiring vitrectomy with membrane stripping and a complete intraocular capsulectomy with repositioning of the 3-piece intraocular lens (IOL) via the sutureless intrascleral (SIS) technique. ⁴

Methods

A 66-year-old woman presented with gradually worsening vision in the left eye 3 weeks after cataract extraction with implantation of a sulcus 3-piece Z9002 (Precision Lens) IOL. She had cataract surgery with implantation of the same model lens in the right eye that did not lead to any complications only 6 weeks before cataract surgery of her left eye. In addition, the patient’s right eye had small, punched-out chorioretinal scars throughout the periphery consistent with presumed ocular histoplasmosis syndrome. Her medical history included hypertension, coronary artery disease, type 2 diabetes mellitus, hypothyroidism, and chronic obstructive pulmonary disease. Her history was negative for risk factors of endogenous endophthalmitis including intravenous drug abuse or presence of an indwelling catheter.

On presentation, the patient’s visual acuity (VA) of the left eye was counting fingers at 3 feet. The right eye’s VA was 20/20. In both eyes, pupils were equally round and reactive to light, eye pressure was 10 mm Hg via Tono-Pen XL Tonometer (Reichert Technologies), and extraocular movements were intact. Slit-lamp examination of both eyes revealed normal surface structures without evidence of injection or keratopathy. In the left eye, anterior segment examination showed 1+ cell and flare with a well-centered posterior chamber IOL and posterior capsular opacification in both eyes without unusual deposits or plaques. The fundus examination revealed vitreous syneresis in both eyes and 3+ vitritis of the left eye. In the left eye, panuveitis and whitish, small (100-200 μm), discrete, circular preretinal lesions along the posterior hyaloid were observed over the macula and retinal periphery, which were presumed to be inflammatory. The patient was initially diagnosed with chorioretinitis and panuveitis.

An 80-mg dosage of oral prednisone and topical difluprednate drops 4 times daily were ordered. The differential diagnosis included sarcoidosis, toxoplasmosis, tuberculosis, syphilis, Lyme disease, rheumatic diseases, and vasculitides. However, results from a laboratory workup including rapid plasma reagin, fluorescent treponemal antibody absorption, Treponema pallidum particle agglutination assay, QuantiFERON-TB Gold Plus (Quest Diagnostics), antinuclear antibody, antineutrophil cytoplasmic autoantibody panel, lysozyme, angiotensin-converting enzyme, and Toxoplasma gondii immunoglobulin G and immunoglobulin M antibody testing as well as findings from a chest X-ray were negative.

Results

At a 1-week follow-up appointment, the patient’s uveitis in the left eye persisted, with some improvement in vitritis. VA improved from counting fingers at 3 feet to 20/100 OS. The lesions then appeared preretinal on improved fundoscopic examination (Figure 1, A and B). The decision was made to perform a pars plana vitrectomy. During vitrectomy, a posterior vitreous detachment was induced and most of the lesions were elevated with the vitreous, confirming their location on the posterior hyaloid interface (Figure 1C). The residual lesions were washed off with a soft-tip cannula. Intravitreal medications that were injected included ceftazidime, vancomycin, amphotericin B, and dexamethasone. Vitreous fluid washings were sent for aerobic, anaerobic, and fungal cultures. P acnes was recovered from anaerobic culture enrichment broth, which was sensitive to penicillin, moxifloxacin, minocycline, and vancomycin. One week postoperatively, the patient’s vitritis and preretinal lesions were almost completely resolved, and her VA was 20/25 OS.

Figure 1.

(A) C-scan of the preoperative macula optical coherence tomography (OCT) image showing distribution of the lesions in front of the retina. (B) B-scan OCT image through one of the lesions in the superior fovea showing its location within the partially detached vitreous face as well as a mild epiretinal membrane. (C) Intraoperative photograph with a soft-tip cannula seen before the induction of the posterior hyaloid detachment showing lesions in the posterior hyaloid throughout the macula (some were already washed away during surgery) and retinal periphery.

Five weeks postoperatively, the patient presented with complaints of floaters in the left eye and decreased vision. On examination, she had 1+ cell and flare in the anterior chamber and 1+ vitritis. The posterior capsule had white deposits (Figure 2A) that were suggestive of a recurrence of P acnes endophthalmitis. Also, an epiretinal membrane formed with a scaffold of preretinal inflammatory tissue extending into the vitreous cavity (Figure 2, B and C). Yttrium aluminum garnet capsulotomy and intravitreal injection of vancomycin and dexamethasone were attempted with no improvement.

Figure 2.

(A) Presentation of recurrent endophthalmitis with lesions on the posterior lens capsule more typical of Propionibacterium acnes. (B and C) B-scan and C-scan optical coherence tomography images of the macula showing epiretinal membrane with a scaffold of preretinal inflammatory tissue extending into the vitreous cavity. (D) Postoperative images of the reimplanted intraocular lens via scleral tunnel technique.

The decision was made to proceed with pars plana vitrectomy, membrane stripping, complete capsulectomy, and IOL repositioning with SIS fixation. Intraoperatively, a vitrectomy was performed, followed by prolapse of the IOL into the anterior chamber. This was followed by a complete intraocular capsulectomy, ensuring no debris was left in the vitreous or on the lens, using a vitreous cutter and Agarwal intraocular forceps. The 3-piece IOL was repositioned with a SIS technique. ⁴ No lesions were noted on the IOL after the capsular material was removed. The haptics were first explanted through previously created sclerotomies under the scleral flaps, then tucked into the scleral tunnels (Figure 2D). Tisseel fibrin glue (Baxter International) was used to close the scleral flaps and conjunctival peritomy. Intravitreal vancomycin and subconjunctival dexamethasone were injected. Vitreous culture showed no recurrent growth of P acnes or other organisms. In the postoperative period, the patient responded well to routine postoperative drops with complete resolution of the iritis and vitritis. After 3 years of follow-up, the patient’s VA remained 20/20 OU with no additional recurrence of endophthalmitis.

Conclusions

P acnes endophthalmitis following surgery was first described in 1976 by Forster et al. ⁵ P acnes is an anaerobic, gram-positive bacillus found on the normal human conjunctiva and eyelids. When describing the pathogenesis of endophthalmitis following cataract surgery, Speaker and colleagues implicated the bacterial flora of the external structures of the eye. ⁶ Cataract surgery is associated with a 0.07% to 0.13% risk of developing postoperative endophthalmitis. ¹

The diagnosis of P acnes endophthalmitis can pose a challenge. P acnes typically presents as a chronic infection, defined as lasting longer than 6 weeks following surgery. Our case, however, highlights the possibility of an earlier onset of P acnes endophthalmitis at 3 weeks. The typical findings include granulomatous uveitis; vitritis; white, intracapsular plaque; and hypopyon. ⁷ In our patient, the novel finding of multiple whitish, small, circular, discrete, preretinal lesions was observed (Figure 1C) without intracapsular plaques, which presented later in the disease course. These lesions appear analogous to the subcapsular lesions and likely present discrete P acnes colony growth.

The diagnosis is further complicated by the limitations of laboratory testing. P acnes growth in anaerobic culture can require 3 to 14 days. ⁸ Vitreous culture results are negative in more than 50% of cases of postoperative endophthalmitis, as was the case in the recurrence of endophthalmitis in our patient; however, the negative findings of a vitreous culture in her recurrence may have been secondary to low yield because the patient's eye had already been vitrectomized. In such cases, microdissection and polymerase chain reaction can be used to identify the causative organism. ⁸ Because early therapy for endophthalmitis is associated with improved visual outcomes, prompt diagnosis is vital. ⁹ In general, a greater degree of inflammation warrants pursuit of more aggressive treatment options. ¹

Management of P acnes infection is especially difficult because of sequestration of bacteria in the capsular bag. Initial treatment of P acnes endophthalmitis includes intravitreal antibiotics and possibly yttrium aluminum garnet capsulotomy, with or without surgical intervention. These treatments are sometimes successful but usually require further surgical intervention including pars plana vitrectomy, partial or total capsulectomy, antibiotic washing of the capsular bag, and/or IOL exchange. ^{10 -13} There is a 40% to 50% recurrence of P acnes endophthalmitis if the IOL or the capsule are not addressed. ³ In this patient, complete capsulectomy was performed and a sutureless reimplantation of the existing IOL was used as a strategy for securing the lens without the need for a lens exchange. We acknowledge that there is a theoretical possibility of microbial contamination in the lens material in some cases ^14,15 ; however, after complete capsular removal from the lens, we believe that the risk of bacterial growth on the lens is negligible. An advantage of repositioning the existing IOL is that this approach reduces the complexity of the procedure by reducing the number of maneuvers necessary to complete the surgery.

In summary, to our knowledge this is the first report of P acnes endophthalmitis presenting initially with panuveitis and discrete preretinal lesions. In the end, the case was definitively managed with a complete capsulectomy with IOL repositioning, which successfully prevented recurrences and preserved 20/20 vision.