The cumulative impact of air pollution on dry eye disease: Evidence from the Korea national health and nutrition examination survey (2017-2020)

Abstract

Purpose This study aimed to assess the association between major air pollutants and dry eye disease (DED), a common yet underrecognized condition whose subtle symptoms and complex pollutant exposures complicate evaluation in population-based settings. Methods Cross-sectional data from the 7th and 8th Korea National Health and Nutrition Examination Survey (2017-2020; n = 13,980) were linked with air pollution records from the National Ambient Air Quality Management Information System. Daily Cumulative Index (CI) values based on SO2, NO2, PM2.5, and PM10 were derived for each region. Gaussian mixture models identified a latent threshold, classifying days as usual, poor, or bad; logistic regression then estimated associations between pollution exposure and DED, adjusting for demographic, clinical, and meteorological factors. Aggregate Air Quality Index(AAQI) values were evaluated for comparison. Results Among 13,980 participants (5989 men; 7991 women), the prevalence of clinical DED was 15.9% (95% CI, 15.2%-16.5%) and was higher in women than in men. In adjusted models, each additional day in a year with a Cumulative Index exceeding the latent threshold was associated with increased prevalence of DED (aOR = 1.04; 95% CI: 1.02-1.06; P < 0.001). By contrast, the annual average of the AAQI was not associated with DED prevalence (P = 0.83). Conclusion Cumulative exposure to severe air pollution was associated with higher DED prevalence, whereas annual average air quality was not. Extreme pollution events may represent a more relevant target for prevention than average exposure levels.