Age-related macular degeneration: prevalence and risk factors from Korean National Health and Nutrition Examination Survey, 2008 through 2011

Objective: To investigate the prevalence and risk factors of age-related macular degeneration (AMD) in the Korean population.

Design: A cross-sectional study using a complex, stratified, multistage, probability-cluster survey, which can produce nationally representative estimates.

Participants: Using the database of Korean National Health and Nutrition Examination Survey from 2008 through 2011, 14 352 participants 40 years of age or older with gradable fundus photographs were included.

Methods: Age-related macular degeneration was determined by fundus photograph. Prevalences of AMDs were estimated. Risk factor analyses were conducted using logistic regression analyses (LRAs).

Main outcome measures: Prevalence and risk factors of AMD.

Results: The prevalence of AMD was 6.62% (95% confidence interval [CI], 6.15%-7.09%) in the Korean population: 6.02% (95% CI, 5.56%-6.48%) were early AMD and 0.60% (95% CI, 0.45%-0.75%) were late AMD. The prevalence of early AMD in women (6.73%; 95% CI, 6.11%-7.35%) was higher than that in men (5.25%; 95% CI, 4.61%-5.89%; P<0.001), and the prevalence of late AMD in women (0.37%; 95% CI, 0.22%-0.52%) was lower than that in men (0.85%; 95% CI, 0.59%-1.12%; P<0.001). However, in multiple LRAs both early and late AMD had no association with gender, house income, residence, sun exposure, or systemic comorbidities, including hypertension, diabetes mellitus, and cardiovascular diseases. Early AMD had positive associations with older age groups (P<0.001), lower education (P = 0.027), occupation (P<0.001), anemia (P = 0.027), hepatitis B surface antigen carrier status (P<0.001), not being overweight (body mass index [BMI], P = 0.032; waist circumference, P = 0.041, in separate analyses), and higher serum high-density lipoprotein (HDL) level (P = 0.046), but not with smoking status. Late AMD had positive associations with age groups (P<0.001), current smokers (P = 0.022), and lower BMI (P = 0.037).

Conclusions: The results suggest that there are 1.21 million individuals with early AMD and 121 000 individuals with late AMD in Korea. Nonoverweight status and higher HDL levels, generally assumed as positive health indicators, as well as anemia and hepatitis B infection had harmful associations with AMD in our study, implying a possible different pathophysiologic process of AMD in Asians compared with that of white persons.