Bacterial Dispersion Associated With Various Patient Face Mask Designs During Simulated Intravitreal Injections

Abstract

Purpose: We sought to investigate bacterial dispersion with patient face mask use during simulated intravitreal injections.

Design: Prospective cross-sectional study.

Methods: Fifteen healthy subjects were recruited for this single-center study. Each participant was instructed not to speak for 2 minutes, simulating a "no-talking" policy, while in an ophthalmic examination chair with an blood agar plate secured to the forehead and wearing various face masks (no mask, loose fitting surgical mask, tight-fitting surgical mask without tape, tight-fitting surgical mask with adhesive tape securing the superior portion of the mask, N95 mask, and cloth mask). Each scenario was then repeated while reading a 2-minute script, simulating a talking patient. The primary outcome measures were the number of colony-forming units (CFUs) and microbial species.

Results: During the "no-talking" scenario, subjects wearing a tight-fitting surgical mask with tape developed fewer CFUs compared with subjects wearing the same mask without tape (difference 0.93 CFUs [95% confidence interval 0.32-1.55]; P = .003). During the speech scenarios, subjects wearing a tight-fitting surgical mask with tape had significantly fewer CFUs compared with subjects without a face mask (difference 1.07 CFUs; P = .001), subjects with a loose face mask (difference 0.67 CFUs; P = .034), and subjects with a tight face mask without tape (difference 1.13 CFUs; P < .001). There was no difference between those with a tight-fitting surgical mask with tape and an N95 mask in the "no-talking" (P > .99) and "speech" (P = .831) scenarios. No oral flora were isolated in "no-talking" scenarios but were isolated in 8 of 75 (11%) cultures in speech scenarios (P = .02).

Conclusion: The addition of tape to the superior portion of a patient's face mask reduced bacterial dispersion during simulated intravitreal injections and had no difference in bacterial dispersion compared with wearing N95 masks.