Cigarette smoking and the natural history of age-related macular degeneration: the Beaver Dam Eye Study.

PURPOSE

To examine the association of current cigarette smoking and pack-years smoked with the incidence and progression of age-related macular degeneration (AMD) and to examine the interactions of current smoking and pack-years smoked with complement factor H (CFH, rs1061170) and age-related maculopathy susceptibility 2 (ARMS2, rs10490924) genotype.

DESIGN

A longitudinal population-based study of AMD in a representative American community. Examinations were performed every 5 years over a 20-year period.

PARTICIPANTS

A total of 4439 participants in the population-based Beaver Dam Eye Study (BDES).

METHODS

Age-related macular degeneration status was determined from grading retinal photographs. Multi-state models were used to model the relationship of current smoking and pack-years smoked and interactions with CFH and ARMS2 with the incidence and progression of AMD over the entire age range.

MAIN OUTCOME MEASURES

Incidence and progression of AMD over a 20-year period and interactions between current smoking and pack-years smoked with CFH and ARMS2 genotype.

RESULTS

The incidence of early AMD over the 20-year period was 24.4%, and the incidence of late AMD was 4.5%. Current smoking was associated with an increased risk of transitioning from minimal to moderate early AMD. A greater number of pack-years smoked was associated with an increased risk of transitioning from no AMD to minimal early AMD and from severe early AMD to late AMD. Current smoking and a greater number of pack-years smoked were associated with an increased risk of death. There were no statistically significant multiplicative interactions between current smoking or pack-years smoked and CFH or ARMS2 genotype.

CONCLUSIONS

Current smoking and a greater number of pack-years smoked increase the risk of the progression of AMD. This has important health care implications because smoking is a modifiable behavior.