Aerosol formation during non-contact "air-puff" tonometry and its significance for prevention of COVID-19 / 中华实验眼科杂志

ABSTRACT

Objective@#To evaluate the aerosol concentration(PM2.5,PM10.0 and aerosol particle number) formation in non-contact "air-puff" tonometry and provide suggestions for medical workers to take appropriate daily protection during the prevalence of 2019-nCoV.@*Methods@#A cross-sectional study was carried out in this study. Thirty healthy subjects were enrolled on February 22, 2020 at Eye Hospital of Wenzhou Medical University. The intraocular pressure (IOP) was measured by non-contact "air-puff" tonometer in the ophthalmic consulting room and the hall with or without masks. PM2.5, PM10.0 and aerosol particles were recorded by air quality detector. The cumulative effects of IOP measurement, PM2.5, PM10.0 and aerosol particle number were analyzed, and the aerosol density of subjects with and without masks was compared.@*Results@#The PM2.5, PM10.0 and aerosol particles produced by the non-contact "air-puff" tonometry and increased with the increase of spray times. The IOP curves of 60 eyes of 30 subjects were measured respectively in two environments of medical consulting room and medical institution hall. It was found that PM2.5, pm10.0 and particle number fluctuated and increased with the increase of IOP measurement person times, showing cumulative effect, and the accumulation speed of aerosol density in hall was faster than that in consulting room. The density of PM2.5 and PM10.0 produced without gauze mask were (53.417±2.306) and (85.350± 3.488) μg/m3, which were higher than those of (50.567±0.862) and (80.617±1.463) μg/m3 with gauze mask. The differences were statistically significant (P=0.028, 0.019).@*Conclusions@#Aerosol can be produced by non-contact "air-puff" tonometer spraying, and it fluctuates with the increase of spraying times, showing a cumulative effect. The aerosol accumulation is higher in the hall with insufficient air circulation. And more aerosol can be produced without gauze mask.