Patient Face Mask Use Not Associated With Endophthalmitis During Intravitreal Injection

Ophthalmologist discussing with senior woman. Aged female is sitting in doctor’s office. They are in hospital during COVID-19 crisis.
The study also suggests that patient-worn face masks do little to reduce the risk.

A study involving 12 institutions across the country found that endophthalmitis rates among patients receiving anti-vascular endothelial growth factor (anti-VEGF) injections while wearing face masks compared with patients not wearing masks were not statistically significant. However, injections administered in clinics with universal face mask policies were associated with significantly lower rates of culture-positive endophthalmitis. These findings were published in Ophthalmology.

Acute-onset bacterial endophthalmitis remains a potentially devastating complication for patients receiving intravitreal anti-VEGF injections. Researchers examined how universal face mask precautions designed to lower the transmission of COVID-19 impacted the risk of post-injection endophthalmitis.

Patients receiving intravitreal anti-VEGF injections between October 1st, 2019 and July 31, 2020 at 12 centers were placed 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.

Of 505,968 intravitreal injections administered to 110,547 eyes, 85 cases of presumed endophthalmitis occurred in the “no face mask” group of 294,514 (0.0289%; 1 in 3,464 injections), and 45 cases occurred in the “universal face mask” group of 211,454 (0.0213%; 1 in 4,699) (odds ratio [OR], 0.74; 95%CI, 0.51–1.18; P =.097). In the “no face mask” group, there were 27 cases of culture-positive endophthalmitis (0.0092%; 1 in 10,908 injections) compared with 9 cases (0.004%; 1 in 23,494) in the “universal face mask” group (OR, 0.46; 95%CI, 0.22–0.99; P =.041). In the “no face mask” group, 3 cases of oral flora-associated endophthalmitis occurred (0.001%; 1 in 98,171 injections) compared with 1 (0.0005%; 1 in 211,454) in the “universal face mask” group (P =.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 with 1.65 [∼20/900] for the “universal face mask” group (P =.022), although no difference was observed 3 months after treatment (P =.764).

Researchers noted that overall endophthalmitis risk was higher with intravitreal aflibercept compared with intravitreal ranibizumab or intravitreal bevacizumab. 

Limitations of this study, according to investigators, are inherent in its retrospective nature and include inconsistent data entry, potential missing data, heterogeneity of injection preferences among physicians, and inconsistency in laboratory testing. While the study examined more than 500,000 intravitreal injections, the findings still may be limited by sample size, particularly when evaluating the role of taping the top of face masks and changes to the rate of oral flora-associated endophthalmitis. Another limitation is the lack of a standardized protocol for intravitreal injections across institutions. Physicians individually determined injection protocols, including the potential use of viscous lidocaine gel, which may alter the risk of endophthalmitis

Disclosure: Some study authors declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.  


Patel SN, Tang PH, Storey PP, et al. The influence of universal face mask use on endophthalmitis risk after intravitreal anti-VEGF injections during the COVID-19 pandemic. Ophthalmol. Published online May 18, 2021. doi:10.1016/j.ophtha.2021.05.010.