Delayed-onset bleb-associated endophthalmitis (1996-2008): causative organisms and visual acuity outcomes

Abstract

Purpose: The purpose of this study was to report the clinical features, organisms, and outcomes of patients with delayed-onset bleb-associated endophthalmitis.

Methods: Retrospective consecutive case series. Patients who were treated for delayed-onset bleb-associated endophthalmitis between January 1, 1996, and July 1, 2008, at a single institution were included. Information on visual acuities, clinical characteristics, causative organisms, and treatment outcomes were collected. Infections within 1 month of glaucoma filtering surgery, inadvertent filtering blebs after cataract surgery, and patients with glaucoma drainage devices were excluded.

Results: A total of 71 eyes from 68 patients were identified. An adjunctive antifibrotic agent was used in 48 eyes (68%). The mean time between surgery and endophthalmitis was 4.8 years (range, 0.1-16; standard deviation, 3.6). The average follow-up time after initial treatment was 37 months (range 1-144; standard deviation, 41). At presentation, 17 eyes (24%) had a bleb leak. Fifty-seven eyes (83%) were culture positive. The most common causative organisms were Streptococcus species in 20 eyes (30%), gram-negative organisms in 19 eyes (28%), and coagulase-negative Staphylococcus in 12 eyes (18%). All gram-positive isolates were sensitive to vancomycin. Nine eyes (13%) eventually underwent evisceration or enucleation secondary to pain and/or poor vision. The main outcome measure was best-corrected visual acuity at the last follow-up examination. Final visual acuities in the initial tap/inject group (n = 45) versus the initial vitrectomy group (n = 24) were as follows: ≥ 20/40 (29% vs. 4.2%), 20/50 to 20/400 (36% vs. 29%), and <5/200 (36% vs. 62%).

Conclusion: Streptococcus species and gram-negative organisms were the most common causative isolates identified in this case series of delayed-onset bleb-associated endophthalmitis. Despite treatment of the infection, visual outcomes were generally poor.