Can face mask wear during anti-VEGF injections reduce endophthalmitis?

This retrospective study assessed how universal face mask wear affects the rates and outcomes of endophthalmitis after anti-VEGF injection.

Study design

The authors evaluated 505,968 injections administered to 110,547 eyes at 12 U.S.-based centers between October 2019 and July 2020. They divided cases into an unmasked group in which neither physician or patient wore a mask, and a universal face mask group in which everyone (physicians, ancillary staff, and patient) wore a mask.

Outcomes

Of the presumed endophthalmitis cases, approximately 0.029% (1 in 3,464 injections) occurred in the unmasked group and 0.021% (1 in 4,699 injections) occurred in the universal face mask group. There were more cases of culture-positive endophthalmitis in the arm that did not wear face masks than in the universal face mask group (27 vs. 9 cases). Oral flora-associated endophthalmitis occurred in 3 unmasked cases and 1 universal face mask case. Although the average logMAR visual acuity at presentation was higher in the unmasked group (2.0 vs. 1.7 logMAR), the difference diminished after 3 months of treatment.

Limitations

This study is limited by its retrospective design. There also were inconsistent data entry, potentially missing data, heterogeneity of physicians' injection preferences, and inconsistency in lab testing. Since there is no standard protocol for intravitreal injections across institutions, physicians chose protocols—including the use of viscous lidocaine gel—which could have altered the risk of endophthalmitis.

Clinical significance

Based on these findings, physicians who did not use face masks during intravitreal injections prior to the pandemic can probably return to their usual routine once face mask restrictions are lifted in clinics.