Bilateral Involvement of Age-Related Macular Degeneration in South Korea: Findings from the Korea National Health and Nutrition Examination Survey 2017–2020

Purpose: To evaluate the bilateral involvement of age-related macular degeneration (AMD) in South Koreans. Methods: This was a cross-sectional study of the Korean National Health and Nutrition Examination Survey (2017–2020). This study included 13,737 participants aged 40 years or older. Participants were evaluated to determine the prevalence of bilateral early and late AMD. In cases in which exudative AMD or geographic atrophy (GA) was diagnosed in a single eye, the fellow eye was evaluated to determine the presence and type of late AMD. Results: The overall prevalence of bilateral AMD was 6.12% (95% confidence interval [CI], 5.63–6.61). The prevalence of bilateral early AMD was 5.71% (95% CI, 5.24–6.18), while that of late AMD was 0.14% (95% CI, 0.08–0.20). The prevalence of the bilateral involvement of late AMD increased with age. A 0.02% prevalence (95% CI, 0.00–0.06) of late AMD was observed in participants aged 50–59. The prevalence increased to 0.08% (95% CI, 0.00–0.18) in participants aged 60–69, while the prevalence in participants aged 70–79 and over 80 was 0.45% (95% CI, 0.12–0.78) and 1.97% (95% CI, 0.75–3.19), respectively. The prevalence of early AMD in one eye and late AMD in the fellow eye was 0.26% (95% CI, 0.16–0.36). Conclusions: An assessment of the incidence of AMD revealed that a significant number of persons had bilateral involvement. The treatment burden may significantly increase for participants with bilateral late AMD compared to those with unilateral involvement. Therefore, the study may be helpful with the establishment of private and national insurance policies.