Objectives: To test whether iron accumulation in the lens following cigarette smoke exposure is the principal mechanism in smoke-related cataractogenesis and to assess the possible protective effect of deferoxamine mesylate treatment against lenticular degeneration with in vivo exposure to cigarette smoke.
Methods: Thirty-two male Wistar rats were randomly divided into 4 equal groups. Groups 3 and 4 rats were exposed to cigarette smoke for 1 hour each day for 90 consecutive days, and groups 1 and 2 rats were treated in a similar manner but exposed only to room air. In addition, deferoxamine was given subcutaneously to groups 2 and 4 rats. Both eyes of all the animals were then enucleated and 1 eye prepared for histopathological examination. The fellow eye was used to measure iron, calcium, zinc, and copper levels.
Results: Significantly higher iron and calcium and lower zinc levels were observed in the lenses of group 3 rats compared with those in the other groups. Similar comparisons performed between groups 1 and 2, 1 and 4, and 2 and 4 did not show any significant difference. Copper concentrations did not differ between groups. Distinct histopathological changes in the anterior lens epithelium, such as hyperplasia, hypertrophy, and epithelial multilayering, and the presence of swollen epithelial cells overlying the posterior lens capsule, observed in group 3 rats, were not present in the other groups.
Conclusions: Cataractogenesis following cigarette smoke exposure in rats was associated with the accumulation of iron, and concurrent deferoxamine therapy prevented such cataract formation.
Clinical relevance: Our results may apply to human cataract formation associated with cigarette smoking, so such pathogenesis may be prevented by concurrent parenteral deferoxamine treatment. Clinical studies are needed, however, to determine the value of this suggestion.