Modifiable risk factors for AMD Author:

Smoking is the best characterized risk factor for AMD(1). The initial observations performed in Caucasian populations from Western countries(2), are now being confirmed in other ethnic groups, such as AfricanAmericans(3), Latino-American(4), or Asian populations(5-7). In most studies, the risk for late AMD was multiplied by 2.5 to 4.5 in current smokers. In addition, the dose-response relationship was explored in some studies(6,8-12). Most of these studies found that the risk for AMD increased with increasing number of cigarettes smoked per day, and, even more, with number of pack-years smoked, which is an indicator of cumulative smoking over the lifetime (mean number of packs smoked/day x duration of smoking (years). Moreover, the risk for AMD appeared to decrease with time from cessation of smoking. Former smokers generally demonstrated a lower risk for AMD than current smokers. Several studies have shown that the risk for AMD in subjects having ceased smoking for more than 20 years was similar to the risk in never smokers(8-10,13). One study suggested that passive smoking is also associated with an increased risk for AMD(9), while this association did not reach statistical significance in another study(14). Finally, smoking appeared to be related to similar risks for both types of late AMD (geographic atrophy and neovascular AMD)(9,13,15-16). By contrast, associations with early AMD were weaker in the vast majority of published studies, and often not statistically significant(8-9,13,15,17-18).