Relationship between socioeconomic and lifestyle factors and cataracts in Koreans: The Korea National Health and Nutrition Examination Survey 2008-2011

Purpose Cataracts are the leading cause of visual impairment and blindness, and therefore early identification and modification of the risk factors for cataracts are meaningful. This study aimed to investigate the relationship between socioeconomic status (SES) and lifestyle factors, and age-related cataracts in South Korea. Methods This cross-sectional study was based on data collected in the 2008-2011 Korea National Health and Nutrition Examination Survey. A total of 15 866 subjects, aged >= 40 years, were included. SES was defined using household income and education level. Sociodemographic, lifestyle, and other associated factors were assessed by health interviews and examinations. Cataracts were diagnosed via slit-lamp examination using the Lens Opacities Classification System III. Results The prevalence of any cataract was 38.9% in men and 42.3% in women (P<0.001). In women, the risk of cataracts increased with decreases in household income (P-value for trend=0.016 and 0.041 in any, and cortical cataract, respectively) and education level (P-value for trend=0.009, 0.027, and 0.016 in any, nuclear, and cortical cataract, respectively) after adjusting for confounding factors. Current smoking was correlated with nuclear cataracts in men (OR 1.21; 95% CI: 1.00, 1.46 in age-adjusted analysis) and cataract surgery in women (OR 2.25; 95% CI: 1.00, 5.04 in multivariate-adjusted analysis). Conclusions Socioeconomic disparities in cataract prevalence were observed in women; current smoking increased the risk of nuclear cataracts in men and surgery in women. Public health interventions focusing on gender differences are warranted to prevent and treat cataracts.