Incidence of bleb-associated endophthalmitis in the United States

Purpose: To evaluate the 5-year incidence rate of blebitis and bleb-associated endophthalmitis in the United States. Methods: In this retrospective cross-sectional study, we utilized a large commercial health insurance claim-based database during 2007-2011 and identified all patients who had a record of trabeculectomy in 2007. These patients were followed until the end of 2011. During the follow-up period, all incidences of blebitis, confirmed bleb-associated endophthalmitis, and presumed bleb-associated endophthalmitis were recorded. Kaplan-Meier survival analysis was utilized to calculate 5-year cumulative incidence rates of blebitis and bleb-associated endophthalmitis following trabeculectomy procedures. Results: Among the 1,461 trabeculectomies included in our analysis, eight cases of blebitis, five cases of confirmed bleb-associated endophthalmitis, and eight cases of presumed bleb-associated endophthalmitis were identified. We found that the 5-year cumulative incidence of blebitis was 0.55% +/- 0.19%. The 5-year cumulative incidence of bleb-associated endophthalmitis was 0.45% +/- 0.2% when only confirmed cases were included and 1.3% +/- 0.34% when presumed cases were also added to the analysis. The mean time from procedure to diagnosis was 45 months for blebitis and 33 months for bleb-associated endophthalmitis. Conclusion: Blebitis and bleb-related endophthalmitis are uncommon in the United States. The 5-year cumulative incidence was 0.55% for blebitis and 0.45%-1.3% for bleb-associated endophthalmitis.