"Face mask contamination during COVID-19 pandemia. Study on patients receiving intravitreal injections".

PURPOSE: To investigate the bacterial growth in the surgical face masks used by patients who received intravitreal injections and study the effect of povidone-iodine on the periocular area (PA) of masks.
METHODS: Forty patients who attended for intravitreal injections were divided in those with less (<4h) and more (>4h) than 4 hours of mask use. Each group was divided depending on the application or not of povidone-iodine in the periocular area (PA) of the mask. Bacterial load was studied on PA and mouth area (MA) samples.
RESULTS: The bacterial load in the PA was higher in the >4h group compared with the <4h group (13.2 vs 48.75 Colony Forming Units/μL; p=0.03). The contamination in the PA significantly decreased after applying povidone-iodine in the >4h group (p=0.01). The use or not of povidone-iodine was strongly correlated to a positive culture (OR=9.0, p=0.00. CI 1.63-49.44).
CONCLUSIONS: Surgical face masks worn for more than 4 hours presents higher contamination in the PA than those with less use. Bacterial load in the PA is reduced with povidone-iodine on masks used for more than 4 hours. This contamination should be considered in the asepsis protocol of intravitreal injections.