Incidence of bleb-associated endophthalmitis in the United States

Kamyar Vaziri,1 Krishna Kishor,1 Stephen G Schwartz,1 Arindel S Maharaj,1 Darius M Moshfeghi,2 Andrew A Moshfeghi,3 Harry W Flynn Jr1 1Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, USA; 2Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA; 3USC Eye Institute, Department of Ophthalmology, University of Southern California Keck School of Medicine, Los Angeles, CA, USA 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. Keywords: bleb, blebitis, bleb-associated endophthalmitis, trabeculectomy