Delayed-Onset Propionibacterium acnes Endophthalmitis in the Absence of Capsular Complex Following Scleral-Fixated Intraocular Lens: A Case Report

Abstract

Purpose:

This work reports a case of delayed-onset Propionibacterium acnes endophthalmitis in a patient with scleral-fixated intraocular lens (IOL), successfully treated with intravitreal antibiotics and steroids.

Methods:

Patient underwent complete ophthalmic examinations over 2 years. Vitreous cultures, optical coherence tomography, anterior segment and fundus photographs, and fluorescein angiogram were performed.

Results:

A 78-year-old man with dislocated IOL underwent IOL removal and scleral-fixated AO60. He did well for 2 months but returned 9 months later with vision loss. Examination revealed low-grade inflammation and multiple IOL opacities. Vitreous culture grew P acnes. He was treated with intravitreal clindamycin followed by dexamethasone for macular edema without IOL explantation. A year after treatment no inflammation or macular edema was noted.

Conclusion:

To our knowledge, this is the first case of P acnes endophthalmitis following scleral sutured IOL. Treatment with intravitreal injections alone, without IOL explantation, was effective, possibly because of the absence of capsular complex.

Introduction

Delayed-onset postoperative endophthalmitis is a rare but potentially sight-threatening complication of cataract surgery. Most cases are secondary to low-virulence microorganisms, of which the most common is Propionibacterium acnes. ¹ Histologically, P acnes is sequestered in the peripheral capsular complex and grows in the form of white deposits or plaques. ^1,2 Of the different strategies that have been used for the treatment of P acnes endophthalmitis, vitrectomy with partial or total capsulectomy and intraocular antibiotic injection is the most efficacious in eradicating the bacteria. ² Intraocular antibiotic injection with or without vitrectomy, by contrast, has been associated with a high rate of recurrence. ² We report a case of culture-positive chronic P acnes endophthalmitis in a patient with absent capsular complex after scleral-fixated intraocular lens (IOL). The patient presented with typical findings of P acnes endophthalmitis and responded to intraocular antibiotic injections alone, with which his symptoms resolved. We hypothesize that the absence of a capsular complex—a potential space for sequestration—allowed for conservative management and complete eradication of the bacteria.

Methods

Case Report

A 78-year-old man with a history of hypertension, prostate cancer, type 2 diabetes, and amblyopia of the left eye was referred for evaluation of vision loss in the setting of a dislocated primary IOL in the left eye. On initial examination the right eye was pseudophakic with best-corrected visual acuity (BCVA) of 20/25, and he had unremarkable findings from anterior segment and fundus examinations. BCVA of the left eye was 20/500 with subjective vision loss, an intraocular pressure (IOP) of 13 mm Hg, and a subluxed IOL (Figure 1). Dilated fundus examination findings were unremarkable (Figure 2).

Figure 1.

Anterior segment photograph showing 3-piece intraocular lens inferiorly dislocated with thickening of the capsular complex.

Figure 2.

Widefield fundus color photograph showing no abnormal findings.

The patient underwent an uneventful pars plana vitrectomy with IOL exchange. A scleral-sutured +21.0-D Bausch + Lomb Akreos A060 IOL was placed and fixated using CV-8 polytetrafluoroethylene (GORE-TEX; W.L. Gore & Associates) sutures. During the surgery a thorough vitrectomy was performed, including removal of the IOL and the capsular and zonular elements, which were significantly opacified. The corneal wound was closed with 10-0 nylon sutures and the conjunctiva was reapproximated with 7-0 vicryl sutures to adequately cover the GORE-TEX sutures. A postoperative course of topical steroids, nonsteroidal anti-inflammatory drugs, and antibiotics was given. The immediate postoperative period was unremarkable. VA in the left eye stabilized to 20/125 with subjective vision improvement, limited by amblyopia.

The patient, who returned home to the Dominican Republic, was lost to follow-up and returned to our clinic 8 months later with complaints of decreased vision and moderate pain in the operative eye. On examination, BCVA in the left eye had decreased to 20/600 with an IOP of 16 mm Hg. The GORE-TEX sutures were well covered by conjunctiva without significant conjunctival injection. There were no corneal infiltrates. Trace corneal edema with multiple small white precipitates over the IOL surface was noted, with cell/flare in the anterior chamber (AC) (Figure 3). The fundus examination, although limited secondary to the anterior segment, had grossly normal findings and ultrasound examination showed no significant vitritis or detachment. An AC tap was performed and sent for microbiological analysis, which had negative results. A uveitis workup was also performed including a nonreactive venereal disease research laboratory test and negative QuantiFERON-TB Gold (Cellestis/Qiagen) results. Given the negative AC tap results, the patient was started on topical prednisolone 1% every 4 hours and followed closely. There was some improvement in the AC inflammation. Subsequent optical coherence tomography revealed significant macular edema (Figure 4), while fluorescein angiography showed diffuse chorioretinal leakage with disc leakage (Figure 5).

Figure 3.

Anterior segment photography. Note the white deposits over the surface of the AO60 intraocular lens.

Figure 4.

Optical coherence tomography macular B-scan showing significant cystoid macular edema.

Figure 5.

Late-phase widefield fluorescein angiogram showing macular petaloid leakage and mild optic nerve leakage.

Given the continued concern for infectious etiology, a vitreous tap was performed that was positive for P acnes susceptible to clindamycin and penicillin G. A sample from the tap was sent for fungal culture and calcofluor stain, which showed negative results. At this point, therapeutic options included IOL removal vs a series of intravitreal antibiotic injections. The patient preferred a conservative approach, which we found reasonable given the absence of remaining capsule-sequestering bacteria. We treated him with a series of intravitreal clindamycin injections based on weekly examinations. Three intravitreal injections of clindamycin were given each 10 to 14 days apart with rapid resolution of uveitis and precipitates. The third injection was combined with dexamethasone to treat the cystoid macular edema recalcitrant to topical steroids. The patient again was lost to follow-up. He was reevaluated 8 months later and had a BCVA of 20/80, IOP of 15 mm Hg, and resolution of the macular edema and inflammation (Figure 6).

Figure 6.

Optical coherence tomography macular B-scan showing resolution of cystoid macular edema.

Results

There are various surgical approaches to place an IOL in an aphakic patient. The use of a transscleral 4-point suture IOL fixation has been validated as a safe technique with acceptable clinical outcomes. ^{3 -5} The AO60 is a hydrophilic, acrylic, foldable IOL that has 4 loop haptics, allowing for a 4-point suture fixation to the sclera. ^3,6 The refractive results are reproducible with current IOL power calculation formulas, which translates to an improvement in BCVA in most patients when using this technique. ⁷ Scleral-fixation techniques theoretically offer an advantage over iris-fixated and AC IOLs with a lower risk of corneal decompensation, intraocular inflammation, or glaucoma. ^{3 -7} Infrequently, however, postoperative complications occur with this technique. The most reported complications include hyphema, hypotony, corneal edema, cystoid macular edema, and ocular hypertension, all of which typically respond to medical management alone. ^{3 -7} There were zero reported cases of delayed-onset postoperative endophthalmitis; however, most series have limited follow-up times up to 1 year. ^{3 -7}

Delayed-onset postoperative endophthalmitis is a rare, potentially sight-threatening complication of cataract surgery. As defined by the Endophthalmitis Vitrectomy Study, delayed-onset endophthalmitis occurs more than 6 weeks after cataract surgery. ¹ Its incidence is lower than acute-onset endophthalmitis and has been estimated to be 0.017%. ⁸ Most cases of delayed-onset endophthalmitis are secondary to low-virulence microorganisms, the most common of which is P acnes, followed by fungus and other gram-positive bacteria (eg, Staphylococcus spp or Corynebacterium spp). ¹ It typically presents as low-grade chronic inflammation that may be challenging to differentiate from other causes of noninfectious uveitis. ^1,2,8 Forster et al made the first observation of P acnes as a causative agent of low-grade endophthalmitis in postoperative eyes in which a fungal infection was suspected. ⁹ The typical findings of white intracapsular deposits or plaque growth associated with low-grade anterior uveitis and mild to moderate visual loss were later described by Meisler. ¹⁰ P acnes accounts for approximately 41% to 100% of all cases of delayed-onset postoperative endophthalmitis. ^1,10

Conclusions

This patient had a unique presentation of P acnes endophthalmitis, with findings that developed after vitrectomy and complete removal of the capsular complex for a dislocated IOL. He presented with chronic low-grade inflammation and presence of white deposits on the IOL. After initial negative findings from an AC tap culture, a vitreous culture yielded P acnes from the broth alone. Although this could possibly represent a contaminant, with a clinical picture of panuveitis with 2 to 3+ cell and flare, diffuse keratic and IOL precipitates, vitritis, and diffuse leakage on fluorescein angiography, we presumed the positive culture results were real and the etiology was infectious in nature, and we treated it as such. A high rate of recurrence with antibiotics alone has been reported in cases of P acnes endophthalmitis; however, these patients had a partial or intact capsular complex. ² In addition, there are reports of successful medical management in patients with prior capsular removal and in those in whom P acnes plaque removal was surgically performed. ^1,2,11

Given the lack of a capsular complex, we opted for a conservative approach with intravitreal injection of antibiotics alone. From the microbiology analysis, the P acnes was susceptible to clindamycin injections, and therefore we proceeded with this medication. After 3 intravitreal injections of clindamycin, the patient achieved resolution of symptoms and a significant improvement in VA. To the best of our knowledge, this is the first report of P acnes endophthalmitis in a patient with sutured scleral-fixated IOL. In cases without capsular remnants, it may be reasonable to initially treat conservatively with intravitreal injection of antibiotics in conjunction with a local steroid. However, the therapeutic approach should be decided on a case-by-case basis, including whether to remove the IOL.