A nationwide cohort study of cigarette smoking and risk of neovascular age-related macular degeneration in East Asian men

Background Few longitudinal studies have evaluated the relationship between cigarette smoking and risk of neovascular age-related macular degeneration (AMD) among Asian populations. This study aimed to prospectively evaluate the association between cigarette smoking and risk of neovascular AMD among Korean men. Methods Men between the ages of 45 and 79 years included in the Korea National Health Insurance Service database from 2002 through 2013. We compared hazard ratios (HR) for neovascular AMD between 64 560 past/current and 64 560 never smokers by 1:1 propensity-matched analysis and 85 267 past/current and 72 347 never smokers by unmatched cohort and propensity-adjusted analysis. Results The risk of neovascular AMD among past/ current smokers was 50% higher than that among never smokers (propensity-adjusted whole cohort analysis: HR, 1.48; 95% CI 1.22 to 1.79; propensity-matched analysis: HR, 1.50; 95% CI 1.22 to 1.84), with the risk more pronounced among current than past smokers (current vs past smokers: propensity-adjusted whole cohort analysis, HR, 1.66; 95% CI 1.35 to 2.04 vs HR, 1.15, 95% CI 0.87 to 1.52; propensity-matched analysis, HR, 1.65; 95% CI 1.32 to 2.05 vs HR, 1.21; 95% CI 0.90 to 1.63). Duration of smoking and daily cigarette consumption was associated with the incidence of neovascular AMD in a dose-dependent manner (p<0.001 for trend). Conclusions Cigarette smoking is associated with a strong risk of neovascular AMD among Korean men. These data highlight the public health impact of smoking on blindness in Asia.