Antioxidants in the progression of cataracts.

Date:

04-Feb-2002

Source

Ophthalmic Epidemiol

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Article

Our eyes are the tools that we use to gather information from our environment. This information not only gives us pleasure but also guides our behavior.1 We take our eyes for granted yet we value them so highly. Taking care of our eyes is critical and the importance of eye examinations cannot be over emphasized. Eye examinations often reveal signs of disease and ocular disorders. Regular examinations can also determine the effects of drugs that are either administered systemically or used directly in the eye itself.

A cataract is a clouding of the lens sufficient to reduce vision. Most cataracts develop slowly as a result of the aging process, and lead to a gradual reduction in vision. The only treatment is surgical extraction of the opacified lens. Remarkable technical innovations have made it possible to remove the cataract while leaving the lens capsule intact. A plastic or silicone lens is then placed in the empty lens capsule, replacing the natural lens, and most generally leading to improved sight in most patients.

A recent study stated that cataracts are one of the leading causes of blindness worldwide. This double masked, randomized, placebo controlled study examined the role of oral antioxidants in the progression of age related cataracts (ARC). The researchers used an antioxidant combination of 600 mg of vitamin E, 18 mg of beta carotene, and 750 mg of vitamin C daily. A total of 445 American and English patients with early ARC qualified, and 297 were randomized. During the course of the study, 231 patients were followed for two years, 158 were followed for 3 years, and 36 were followed for 4 years. The status of these patients was checked every four months. The results were measured by the 'increase percentage pixel opaque'. After two years of treatment, there was a small improvement in the US patients, and after three years, there was greater improvement in the Americans. The English patients did not show considerable progress with the vitamin supplementation though it is unknown why. The authors concluded, " Daily use of the afore-mentioned micronutrients for three years produced a small deceleration in progression of ARC."2

References

1. Horton JC. Disorders of the eye. In: Fauci AS, Braunwald E, Isselbacher KJ, et al. eds.Harrison’s Principles of Internal Medicine 14th ed. New York, McGraw-Hill; 1998:159-172.
2. Chylack LT. The Roche European American Cataract Trial (REACT): A randomized clinical trial to investigate the efficacy of an oral antioxidant micronutrient mixture to slow progression of age-related cataract. Ophthalmic Epidemiol. Feb 2002;9(1):49-80.