Association between Three Heavy Metals and Dry Eye Disease in Korean Adults: Results of the Korean National Health and Nutrition Examination Survey

Abstract

Purpose: To investigate the associations between blood heavy metal concentrations and dry eye disease usinga Korean population-based survey. Methods: This study included 23,376 participants >40 years of age who participated in the Korean NationalHealth and Nutrition Examination Survey from 2010 to 2012. Blood concentrations of lead, cadmium, and mercurywere measured in all participants. The associations between blood heavy metal concentrations and dryeye disease were assessed using multivariate logistic regression analyses. Results: After adjusting for potential confounders, including age, sex, lifestyle behaviors and sociodemographicfactors, the analyses revealed an increased odds ratio (OR) for dry eye disease with higher blood mercuryconcentrations (tertile 2: OR, 1.22; 95% confidence interval [CI], 0.91 to 1.64; tertile 3: OR, 1.39; 95% CI, 1.02to 1.89; p = 0.039). The prevalence of dry eye disease was not associated with blood lead (tertile 2: OR, 1.15;95% CI, 0.87 to 1.51; tertile 3: OR, 0.83; 95% CI, 0.59 to 1.16; p = 0.283) or cadmium (tertile 2: OR, 1.05; 95%CI, 0.77 to 1.44; tertile 3: OR, 1.15; 95% CI, 0.84 to 1.58; p = 0.389) concentrations. There were no significantassociations between any of the three heavy metals and dry eye disease in males after adjusting for potentialconfounding factors, but blood mercury concentrations in females were associated with dry eye disease (tertile2: OR, 1.18; 95% CI, 0.83 to 1.69; tertile 3: OR, 1.58; 95% CI, 1.12 to 2.24; p = 0.009). Conclusions: Mercury concentrations in blood were associated with dry eye disease. Our results suggestedthat controlling environmental exposure to mercury may be necessary to reduce the incidence of dryeye disease.