Further observations on the association between smoking and the long-term incidence and progression of age-related macular degeneration

Objective: To examine the association between smoking and the 15-year cumulative incidence of age-related macular degeneration (AMD). Methods: Population-based longitudinal cohort study of people in Beaver Darn, Wisconsin, who were aged 43 to 84 years (N=4926) in 1987-1988. Participants were examined in 1988-1990 and were reexamined at 5-year intervals during a 15-year period. Age-related macular degeneration status was determined by grading stereoscopic color fundus photographs. Results: Controlling for age, sex, and baseline AMD severity, people who were current smokers at baseline, compared with those who never smoked, were at increased risk of incident early AMD (odds ratio, 1.47; 95% confidence interval, 1.08-1.99; P=.01) and for progression of AMD (odds ratio, 1.43; 95% confidence interval, 1.05-1.94; P=.02) during a 15-year follow-up. There were few associations of specific characteristics of smoking (eg, intensity, pack-years smoked, duration, and age at initiation and quitting) with AMD outcomes. Conclusions: Smoking appears to be related to the long-term incidence and progression of AMD. This has important health care implications because early AMD increases the risk of developing late AMD and smoking behavior is modifiable.