Surgical masks effectiveness have time limit during intravitreal injections

Patients undergoing injections during the COVID-19 pandemic experienced increases in bacterial contamination of the periocular area of their surgical face masks when the masks were worn for longer than 4 hours, report Spanish researchers.

Spanish investigators reported increases in bacterial contamination of the periocular area of the surgical face masks worn by patients during the COVID-19 pandemic who were undergoing intravitreal injections when the masks had been worn for longer than 4 hours.1

Application of povidone-iodine can help reduce that bacterial load, according to Juan Marín-Nieto, MD, and colleagues from the Department of Ophthalmology, University Hospital Virgen de la Victoria, Málaga, Spain.

These results were reported after 40 patients who visited the hospital to undergo intravitreal injections were divided based on the amount of time they wore their masks, i.e., for less than and more than 4 hours.

The 2 groups were then divided further based on the use or no use of application of povidone-iodine to the periocular area of the mask.

Dr. Marín-Nieto and colleagues studied the bacterial growth in both the periocular and mouth areas of the masks.

Bacterial growth
A comparison of the 2 groups by the amount of time the masks were worn showed that those in the group with longer duration of mask wear had significantly (p = 0.03) higher colony-forming units (cfu) in the periocular area compared with those with shorter mask wear, respectively, 48.75 cfu vs. 13.2 cfu.

When povidone-iodine was applied to the periocular area, the degree of bacterial contamination decreased significantly (p = 0.01) in the group with longer mask wear.

The authors reported that the use or non-use of povidone–iodine was correlated strongly with a positive culture (odds ratio, 9.0, p = 0.00; confidence interval, 1.63–49.44).

They concluded that when face masks are worn for longer than 4 hours, there willbe higher levels of bacterial contamination in the periocular area compared with the wearing of masks for durations shorter than 4 hours.

In addition, application of povidone-iodine is very useful for reducing the bacterial contamination than the periocular area and should be considered as part of the asepsis protocol for intravitreal injections.

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1. Marín-Nieto J, Reino-Perez C, Santillana-Cernuda G, et al. Face mask contamination during Covid-19 pandemia. A study on patients receiving intravitreal injections. Retina 2021;41:2215-20.