Sunlight exposure and eye disorders in an economically active population: data from the KNHANES 2008-2012

BACKGROUND: Sunlight exposure is a major risk factor for eye disorders. Most outdoor workers cannot avoid sunlight exposure. This study aimed to analyze the relationship between outdoor sunlight exposure and eye disorders in an economically active population. METHODS: This study analyzed the 2008–2012 Korea National Health and Nutritional Examination Survey data. Sunlight exposure was categorized as < 5 hours and > 5 hours. We also analyzed the dose-dependent relationship between exposure to sunlight and eye disorders (cataracts, pterygium, and age-related macular degeneration [AMD]) using data from 2010 to 2012 by subdividing the exposure groups into < 2 hours, 2–5 hours, and ≥ 5 hours. Eye disorders were diagnosed by an ophthalmologist. The study participants were stratified by sex, and the results were analyzed using the χ(2) test and multiple logistic regression analysis. RESULTS: In the female group, the odds ratio of pterygium in the high-level sunlight exposure group was 1.47 (95% confidence interval [CI]: 1.15–1.89). Regarding AMD, the odds ratios were 1.42 (95% CI: 1.16–1.73), 1.33 (95% CI: 1.03–1.73), and 1.58 (95% CI: 1.15–2.16) in the total, male, and female groups, respectively. Analysis of the dose-response relationship revealed that the odds ratios of pterygium in the high-level sunlight exposure subgroups of the total and female groups were 1.62 (95% CI: 1.25–2.08) and 2.00 (95% CI: 1.39–2.88), respectively. CONCLUSIONS: This study demonstrated a relationship between sunlight exposure and eye disorders in an economically active population. Women were found to be especially vulnerable to pterygium. However, additional prospective studies to clarify the pathophysiology of pterygium are needed.