Natural therapies for ocular disorders, part one: diseases of the retina.

Diseases of the retina are the leading causes of blindness throughout the world. Evidence points to potential benefit from nutritional and botanical interventions for the prevention and treatment of several of these conditions, including macular degeneration, diabetic retinopathy, retinopathy of the newborn, and retinitis pigmentosa. Epidemiological evidence points to the potential of antioxidant vitamins E and C, carotenoids, zinc, and selenium in the prevention and possible treatment of macular degeneration. In addition, dietary components such as red wine-high in important flavonoids-and fruits and vegetables high in carotenoids appear to offer some protection. While diabetic retinopathy can best be prevented by maintaining good blood sugar control, there are a number of nutrients and botanicals which may help prevent and treat retinopathy by inhibiting protein glycosylation, stabilizing collagen, decreasing capillary permeability, and providing important antioxidant effects. Extensive research on the use of vitamin E for the prevention of retrolental fibroplasia (retinopathy of the newborn), despite yielding promising results, has not resulted in incorporation of vitamin E into conventional standards of care protocols. Retinitis pigmentosa resembles the retinal damage seen in taurine-deficient cats. While patients with retinitis pigmentosa do not appear to be deficient in taurine, they appear to have faulty cellular uptake of this important amino acid. Disturbed utilization of vitamin A also appears to play a part in retinitis pigmentosa, and a subgroup of patients benefit from supplementation.