Drugs for glaucoma, age-related macular degeneration, bacterial conjunctivitis, and dry eyes are reviewed here. Ophthalmic drugs can have local and systemic adverse effects. In addition, for some elderly patients, the complexity of self-administering numerous ophthalmic drugs may be the limiting factor in their ability to care for themselves. Drugs for the treatment of allergic conjunctivitis will be reviewed in a future issue of Treatment Guidelines on Drugs for Allergic Disorders.

Cataracts are the leading cause of blindness worldwide because cataract surgery is not available to most people in developing countries.

Many patients ask their physicians whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamin supplements.

Patients may be asking about Airborne, a dietary supplement that is being heavily promoted for prevention and treatment of colds. It contains 7 herbal extracts, 3 vitamins, 2 amino acids, selenium, zinc and many other ingredients. Airborne Jr is available for children. There are some concerns. First, there is no conclusive evidence that this product or any of its ingredients prevents colds or shortens their duration. Second, the adult tablet contains 1 g of vitamin C, and the directions for use advise taking 1 tablet at the first sign of a cold and repeating the dose every 3 hours as necessary. Vitamin C in doses higher than 1 g increases oxalate and urate excretion and may cause kidney stones (EN Taylor et al, J Am Soc Nephrol 2004; 15:3225). Third, the safety of this herbal extraction combination has not been established. And with herbs and dietary supplements in general, we only have the manufacturers' word on the label for what's in them.

High doses of beta carotene, vitamin C, vitamin E and zinc oxide are now being promoted to the general public to "preserve eye health" (Ocuvite PreserVision), "promote retinal and visual health" (VisiVite) and "preserve healthy vision" (ICaps). Internet advertisements for these products all refer to a clinical trial, the Age-Related Eye Disease Study (AREDS), which was conducted in patients with age-related macular degeneration (AMD).