Smoking and lens optical density

Epidemiological evidence indicates that smoking increases the risk of age-r elated cataract. No information is currently available, however, on the eff ects of smoking on the lens prior to cataract development. In this study, w e relate smoking behavior to lens optical density (OD) in younger individua ls without frank cataract. Fifty three never smokers and 41 current smokers were compared directly. Thirty one past smokers were tested to examine the relationship between years since smoking cessation and lens OD. Lens OD wa s measured psychophysically by comparing scotopic thresholds obtained at 41 0 (measuring) and 550 nm (reference). Stimuli were presented in Maxwellian view. The smokers in the sample smoked an average of 17.3 +/- 11.3 cigarett es/day for 20.4 +/- 12 years. No significant differences (other than in fat intake) were found between the smokers and nonsmokers in in's color, dieta ry patterns, or age. Despite their overall similarity, lens OD was signific antly (p = 0.005) higher in the smokers. Moreover, we found a significant d ose-response relationship (p = 0.02) between smoking frequency and lens OD. There was also a weak relationship between smoking frequency and lens OD f or past smokers (p = 0.06), but no relationship between lens OD and years s ince smoking cessation. Our data indicate that smoking is directly related to age-related increases in lens OD throughout life and that these increase s persist even after smoking cessation. (C) 1999 The College of Optometrist s. Published by Elsevier Science Ltd. All rights reserved.