Incidence of Endophthalmitis after Intravitreal Injections: Risk Factors, Microbiology Profile, and Clinical Outcomes.

PURPOSE: To report the incidence and characteristics of endophthalmitis after intravitreal injections (IVI) of antivascular endothelial growth factor agents and triamcinolone acetonide.

METHODS: Patients' medical records were retrospectively reviewed from January 2009 to June 2016, and the incidence, risk factors, clinical and microbiological characteristics of post-IVI endophthalmitis were evaluated.

RESULTS: The total number of intravitreal injections given, which included ranibizumab, bevacizumab, and triamcinolone acetonide, was 20,566, of which 27 cases developed endophthalmitis, giving an overall incidence of 0.131%. Significant reduction (p < 0.003) in incidence of endophthalmitis was observed in patients who received prefilled compounded bevacizumab injections (0.050%) compared to multiple bevacizumab injections from a single vial (0.235%). In the triamcinolone acetonide group, the incidence was 0.26%. Staphylococcus species were isolated from 18 cases (67%), and all strains were sensitive to vancomycin.

CONCLUSIONS: Adherence to strict aseptic protocols and use of prefilled compounded bevacizumab injections reduces the rate of post-IVI endophthalmitis.