Smoking and choroidal thickness in patients over 65 with early-atrophic age-related macular degeneration and normals

Objective To compare macular choroidal thickness between cigarette smokers, those with a history of smoking, and nonsmokers in patients over 65 years of age with early-atrophic age-related macular degeneration (AMD) and normals. Methods Prospective, consecutive, observational case series. Enhanced depth imaging spectral domain optical coherence tomography 12-line radial scans were performed and choroidal thickness manually quantified at 84 points in the central 3mm of the macula. Data of normals, soft drusen alone, and soft drusen with additional features of early AMD were compared. A multivariate analysis of variance (MANOVA) model, controlling for age, was constructed to evaluate the effect of smoking history and AMD features on choroidal thickness. Results A history of smoking was significantly associated with a thinner choroid across all patients via logistic regression (P = 0.004; O.R. = 12.4). Mean macular choroidal thickness was thinner for smokers (148 +/- 63 mu m) than for nonsmokers (181 +/- 65 mu m) among all diagnosis categories (P 0.003). Subgroup analysis of patients with AMD features revealed a similar decreased choroidal thickness in smokers (121 +/- 41 mu m) compared with nonsmokers (146 +/- 46 mu m, P = 0.006). Bivariate analysis revealed an association between increased pack-years of smoking and a thin choroid across all patients (P<0.001) and among patients with features of early AMD (P<0.001). Both the presence of features of macular degeneration (P<0.001) and a history of smoking (P = 0.024) were associated with decreased choroidal thickness in a MANOVA model. Conclusion Chronic cigarette smoke exposure may be associated with decreased choroidal thickness. There may be an anatomic sequelae to chronic tobacco smoke exposure that underlies previously reported AMD risk.