US SCIENTISTS are working with an antioxidant they say could prevent or cure cataracts, macular degeneration and other degenerative eye disorders.

The research group, headed by Dr Nuran Ercal, professor of chemistry at Missouri University of Science and Technology, is studying eye drops prepared with the antioxidant N-acetylcysteine amide (NACA) as a treatment for these eye conditions.

Ercal says NACA is an improvement over another experimental treatment, the antioxidant N-acetylcysteine (NAC), because it passes more easily across cell membranes, allowing the medication to be used in lower doses.

NACA’s characteristics as a drug have been improved by making pass cellular membranes more easily, says Ercal.

"And because NACA can be administered at a lower dose, the drug has a greater therapeutic index, and lowers risks of side effects traditionally associated with NAC.

"NACA is also an excellent source of glutathione, a cell’s main antioxidant power, which is diminished during degenerative eye disorders," she says.

Vision loss from age-related eye disorders affects more than 30-million people in the US alone, and is expected to double in the coming decades. The total annual cost of all services related to vision problems exceeds $2bn, Ercal says.

"NACA eye drops could drastically reduce these costs, and represent an alternative to costly surgery, while greatly improving the quality of life for those afflicted" says Ercal.

Ercal and her team have been testing NACA on HIV-related problems, lead poisoning and other toxicities for 10 years. About four years ago they began testing it on eye disorders.

Ercal says further testing will help establish appropriate dosage and frequency, as well as possible side effects and other factors. She says successful results using animal subjects may eventually support the viability of human usage.