Endophthalmitis after filtering surgery with mitomycin

Objective: To identify the incidence, causative organisms, and clinical outcomes of eyes with bleb-associated endophthalmitis after glaucoma filtering procedures with adjunctive mitomycin. Methods: Retrospective analysis of 773 consecutive eyes that underwent glaucoma filtering surgery at the Bascom Palmer Eye Institute, Miami, Fla. The course of 609 eyes from 485 patients with a minimum of 3 months of follow-up were reviewed. Results: Mean follow-up was 16.0±11.5 months (range, 3-48 months). Of the 609 eyes, 13 (2.1%) developed bleb-associated endophthalmitis an average of 18.5±13.2 months after surgery (range, 1-45 months). The incidence of bleb-associated endophthalmitis was significantly greater after inferior trabeculectomy (7.8% per patient-year) than after superior trabeculectomy (1.3% per patient-year) by Kaplan-Meier estimates (P=.02, log rank test). The cumulative incidence was 13% for inferior limbal blebs and 1.6% for superior limbal blebs. Nine (69.2%) of the 13 eyes were culture positive. Streptococcus sanguis and Haemophilus influenzae (6/13 [46.2%]) were the most frequent causative organisms. The mean increase in intraocular pressure after endophthalmitis treatment was 1.2 mm Hg, with a mean decrease in visual acuity of 1.42 logMAR units. Eight (61.5%) of the 13 eyes had a final acuity of 20/400 or better. Conclusions: The incidence of bleb-associated endophthalmitis after guarded filtering surgery performed with adjunctive mitomycin is higher than the reported rate in eyes undergoing filtering surgery without the use of antifibrotic agents (0.2%-1.5%). Inferior limbal trabeculectomy carries the highest risk of infection. Eyes with mitomycin blebs maintained excellent filtration capacity. However, after treatment of the infection, the visual outcomes were generally poor.