Endophthalmitis Following Intravitreal Injections of Anti-Vascular Endothelial Growth Factor Agents with 0.05% Aqueous Chlorhexidine versus 5% Povidone-Iodine as Ocular Antiseptics

Abstract

Purpose : Topical Povidone-Iodine (PI) is a widely used ocular surface antiseptic for intravitreal injections and is associated with significant ocular discomfort in some patients. In limited studies, aqueous chlorhexidine (CHX), as an alternative antimicrobial to PI, has been associated with a low post-injection endophthalmitis (PIE) rate and less ocular discomfort compared to PI. This study compares the rates and outcomes of PIE for patients pre-treated with 5% PI and 0.05% CHX.

Methods : This was a retrospective, single center, comparative cohort study of patients receiving intravitreal anti-VEGF injections from January 1, 2019, to November 30, 2021. Injection preparation with PI or CHX and cases of PIE were compiled using electronic health records and billing code data. The primary outcomes were the rate of endophthalmitis, culture results, and visual acuity. LogMAR visual acuity was determined at the time of causative anti-VEGF injection, endophthalmitis presentation, and 3-month follow-up.

Results : A total of 68,334 intravitreal injections were administered by 13 retinal specialists during the study period. 13 of 33,064 (0.0393%; 1 in 2,543 injections) cases of presumed endophthalmitis occurred in the PI group, and 9 of 35,270 (0.0255%; 1 in 3,918 injections) cases in the CHX group (OR=0.65; 95% CI 0.27–1.52; p=0.319; Table 1). For the PI group, there were 2 culture-positive endophthalmitis cases (0.00605%, 1 in 16,532), compared to 2 cases in the CHX group (0.00567%, 1 in 17,635) (OR=0.94; 95% CI 0.13–6.66; p=0.949; Table 1). No significant difference was observed in visual acuity between PI and CHX at causative injection (p=0.41), endophthalmitis encounter (p=0.45), and 3-month follow-up (p=0.45; Table 2).

Conclusions : There was no significant difference in the rate of PIE and visual acuity in the CHX group compared to the PI group. Further multicenter studies are needed to further evaluate the efficacy and safety of CHX compared to PI for intravitreal injection preparation.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Table 1. Rates of presumed endophthalmitis and culture-positive endophthalmitis in the Chlorhexidine vs. Povidone-Iodine group.

 

Table 2. Mean logMAR visual acuity at time of causative injection, endophthalmitis presentation, and 3-month follow-up in the Chlorhexidine vs. Povidone-Iodine group.