The potential preventive effects of vitamins for cataract and age-related macular degeneration.

Age-related cataract and age-related macular degeneration (AMD) are important public health problems. Approximately 50% of the 30 to 50 million cases of blindness worldwide result from unoperated cataract. In the US and other developed countries AMD is the leading cause of blindness, but age-related cataract remains the leading cause of visual disability. Age-related cataract and AMD represent an enormous economic burden. In the United States more than 1.3 million cataract extractions are performed annually at a cost of approximately $3.5 billion. Much of the experimental research on the etiology of cataract and AMD has focused on the role of nutritional antioxidants (vitamin C, vitamin E, and carotenoids). Evidence from epidemiologic studies support a role for nutritional antioxidants in delaying the onset of these age-related vision disorders. Although it is not yet possible to conclude that antioxidant nutrients have a role in prevention of cataract or AMD, a summary of the epidemiologic evidence suggests that it is prudent to consume diets high in vitamins C and E and carotenoids, particularly the xanthophylls, as insurance against the development of cataract and AMD.