The influence of universal face mask use on endophthalmitis risk after intravitreal anti-VEGF injections during the COVID-19 pandemic

Abstract Objective Routine use of face masks for patients and physicians during intravitreal anti-vascular endothelial growth factor (VEGF) injections has increased with the emergence of the COVID-19 pandemic. This study evaluates the impact of physician, ancillary staff, and patient face mask use on rates and outcomes of post-injection endophthalmitis. Design Retrospective, multicenter, comparative cohort study Participants Eyes receiving intravitreal anti-VEGF injections from 10/1/2019 to 7/31/2020 at twelve centers from the United States of America. Intervention Cases were divided into a “no face mask” group if no face masks were worn by the physician or patient during intravitreal injections or a “universal face mask” group if face masks were worn by the physician, ancillary staff, and patient during intravitreal injections. Main Outcome Measures Rate of endophthalmitis, microbial spectrum, and visual acuity. Results Of 505,968 intravitreal injections from 110,547 eyes administered, 85 of 294,514 (0.0289%; 1 in 3,464 injections) cases of presumed endophthalmitis occurred in the “no face mask” group, and 45 of 211,454 (0.0213%; 1 in 4,699) cases occurred in the “universal face mask” group (odds ratio [OR], 0.74; 95%CI, 0.51–1.18; p=0.097). In the “no face mask” group, there were 27 cases (0.0092%; 1 in 10,908 injections) of culture-positive endophthalmitis compared to 9 cases (0.004%; 1 in 23,494) in the “universal face mask” group (OR, 0.46; 95%CI, 0.22–0.99; p=0.041). Three cases of oral flora-associated endophthalmitis occurred in the “no face mask” group (0.001%; 1 in 98,171 injections) compared to one (0.0005%; 1 in 211,454) in the “universal face mask” group (p=0.645). Patients presented a mean (range) 4.9 (1-30) days after the causative injection, and mean logMAR visual acuity at endophthalmitis presentation was 2.04 [∼20/2200] for “no face mask” group compared to 1.65 [∼20/900] for the “universal face mask” group (p=0.022), although no difference was observed three months after treatment (p=0.764). Conclusion In a large, multicenter, retrospective study, physician and patient face mask use during intravitreal anti-VEGF injections did not alter the risk of presumed acute-onset bacterial endophthalmitis, but there was a reduced rate of culture-positive endophthalmitis. Three months following presentation, there was no difference in visual acuity between the groups.