Endophthalmitis Incidence After Intravitreal Injection of Anti-VEGF Agents with Povidone-Iodine vs. Aqueous Chlorhexidine Antisepsis.

Purpose: To evaluate the incidence of post injection endophthalmitis (PIE) following intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents in eyes prepared with topical 5% povidone-iodine (PI) or 0.05% aqueous chlorhexidine (AqCHX) as antisepsis.

Design: Retrospective, single-center, comparative cohort study PARTICIPANTS: Individuals who received at least one intravitreal anti-VEGF injection with use of PI or AqCHX as antisepsis.

Methods: For all patients receiving intravitreal anti-VEGF injections at Austin Retina Associates between March 1, 2015 and November 1, 2023, all injections and cases of suspected PIE were identified with billing codes and confirmed with review of electronic medical record data. Eyes that presented following injection with pain and/or decreased vision warranting treatment with intravitreal antibiotics were considered suspected PIE cases. Eyes were grouped based on preparation with PI or AqCHX.

Main outcome measures: The primary outcomes were incidence of suspected and culture-positive PIE and visual acuity at 3 months post endophthalmitis.

Results: A total of 302,474 intravitreal injections were administered during the study period. Within the PI group, 59 cases of suspected PIE occurred following 267,190 injections (0.022%; 1 in 4,529 injections) compared to 5 cases following 35,284 injections (0.014%; 1 in 7,057 injections) in the AqCHX group (p=0.34). For the PI group, there were 10 culture-positive PIE cases (0.0037%, 1 in 26,719 injections) compared to 0 cases in the AqCHX group (p=0.25). At 3-months post-infection, average visual acuity in the PI group was 0.97 (∼20/200) and 1.4 (∼20/500) in the AqCHX group (p=0.41). When controlling for prefilled syringe status, there was no difference in rates of PIE between antisepsis groups (p=0.23).

Conclusions: The incidence of endophthalmitis following intravitreal injection is low with no difference in the rates of infection with eyes prepared with topical PI compared to AqCHX. Topical AqCHX is a safe and effective antiseptic alternative to PI for the prevention of endophthalmitis following intravitreal injection.