Clinical Impact of Ambient Particulate Matters on Dry Eye Disease

Purpose: Dry eye disease (DED) has become a common ocular surface disorder in the recent decades, which can be influenced by environmental factors. This study aimed to examine the clinical association between DED and ambient air pollutants.Methods: A total of 216 patients (18 patients per each month) diagnosed with DED were enrolled in this retrospective study. Ocular surface disease index (OSDI), tear film breakup time (TFBUT), fluorescein corneal staining (FCS), and Schirmer’s test 1 (ST1) were examined. The monthly concentrations of air pollutants in 2018 were obtained from the data released by the Korean Ministry of Environment. Based on the mean of PM10 and PM2.5, subgroup with exposure to low (L–PM) or high concentration of PM (H–PM) was analyzed.Results: Patients had moderate DED as high OSDI, low TFBUT, increased FSC, and decreased ST1. During the year 2018, monthly variation of PM showed that May to October was the period of L-PM and January to April and November to December was the period of H-PM. In subgroup analysis, patients in H-PM showed significantly higher OSDI, FCS, and lower ST1 compared to in L-PM. However, there was no significant difference in TFBUT between subgroups.Conclusions: DED was more severe in the period of H-PM than L-PM even though there was no difference in tear film instability between both periods. Ambient inflammatory factors including PM might deteriorate ocular surface as well as tear secretion, resulting in aggravating DED.