Incidence of Acute Endophthalmitis after Intravitreal Antivascular Endothelial Growth Factor Injection in Age-related Macular Degeneration

PURPOSE: Antivascular endothelial growth factor (anti-VEGF) agents are routinely intravitreously injected to treat neovascular age-related macular degeneration (AMD). Postoperative endophthalmitis, a side effect after intravitreal anti-VEGF injection, has been reported to have a low incidence but may threaten vision. In this study, we aimed to analyze the incidence of acute endophthalmitis after intravitreal anti-VEGF injection and associated risk factors in patients with neovascular AMD in South Korea. METHODS: Using the health claims data recorded in the Korean National Health Insurance System database, we identified newly developed neovascular AMD cases from 2010 through 2019. Acute endophthalmitis was defined as a case of invasive treatment for accompanying symptoms. All statistical analyses were performed with a significance level p < 0.05. To find risk factors, we used univariate and multivariable Poisson regression. RESULTS: The overall incidence of acute endophthalmitis was 0.019% (p = 0.21) during the 10-year period: 0.025% for aflibercept injection and 0.014% for ranibizumab injection. The incidence was higher in metropolitan city residents than in Seoul (incidence rate ratio [IRR], 1.96; 95% confidence interval [CI], 1.02–3.79; p = 0.04) and was higher for aflibercept injections than for ranibizumab injections (IRR, 1.82; 95% CI, 1.17–2.82; p = 0.01). However, in multivariate analysis, only aflibercept injections showed a significant effect on the incidence of acute endophthalmitis (IRR, 1.80; 95% CI, 1.16–2.79; p = 0.01). CONCLUSIONS: The incidence of acute endophthalmitis after intravitreal anti-VEGF injections was generally low, and aflibercept was revealed as a significant risk factor.