Abstract
Purpose :
This research examines association of indoor airborne microbial concentration with dry eye measures among Miami veterans.
Methods :
Subjects with normal external anatomy were enrolled in the study. All subjects underwent a clinical evaluation that included assessment of DE signs, such as conjunctival staining and tear film break up time (TBUT). Within 7 days of clinical visits, a home visit was conducted in which air was sampled (at a flow rate of 28 l /minute) using bioaerosol impactors with nutrient (with bovine serum used for bacteria) and soya (used for fungi and mold) media. Samples were incubated for 48h at 37°C and 5% CO2. Number and distinct type of microbial colonies were recorded. Data on indoor temperature, humidity, and particulate matter (PM) concentration and home characteristics, such as floor type, were collected. DE signs and symptoms were examined with respect to number of microbial communities and home environmental characteristics using regression models adjusting for confounders. Since homes with elevated humidity and temperature had relatively high microbial concentration (Figure 1), number of colonies in both types of petri dish were instrumented on the interaction of indoor humidity and temperature.
Results :
165 subjects participated in a home and clinical visit, and of these, 65 of completed two clinical and home visits. Most subjects were elderly male (mean age 59 y; 85% male) and more than 50% received DE diagnosis. Both nutrient and soya petri dishes showed elevated concentration and number of colonies were significantly higher on soya media as compared to nutrient media (65 colonies versus 75 colonies; p < 0.01). The instrumented indoor microbial concentration emerged a significant predictor of corneal epithelial disruption in both univariate and multivariate analyses (odds ratio = 8.14; 95% CI= 1.43 to 46.23; p < 0.05 for soya) (Table 1).
Conclusions :
We observed elevated microbial concentration in Miami, especially in older homes with high humidity and temperature, which was associated with (positive) detection of corneal epithelia disruption. Given elevated exposure to airborne microorganisms is associated with initiation and exacerbation of a various diseases, it is important to mitigate microbial exposure indoors. Simple measures, such as controlling humidity between 40 to 50%, keeping temperature below 21°C, and changing air filter every 1-3 months, can mitigate microbial growth and DE disease burden.
This is a 2020 ARVO Annual Meeting abstract.