Eyedrops, prepared with the antioxidant N-acetylcysteine amide (NACA), have been used as treatment for the prevention or healing of cataracts, macular degeneration, and other degenerative eye disorders.

Researchers at the Missouri University of Science and Technology researched these eyedrops and have discovered that they are an improvement over a separate experimental treatment using N-acetylcysteine (NAC), due to easier movement across cell membranes, permitting low dosages of the medicine to be just as efficient.

Dr. Nuran Ercal, head researcher and the Richard K. Vitek/Foundation for Chemical Research Endowed Chair in Biochemistry and professor of chemistry at Missouri S&T, explains:

“NACA’s characteristics as a drug were improved over NAC by neutralizing the carboxylic group of NAC, which makes the NACA pass cellular membranes easily. And because NACA can be administered at a lower dose, the drug has a greater therapeutic index and lowers the risk 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.”

Age-related eye disorders that induce vision loss are common, affecting over 30 million people in the United States, and are projected to double in the coming years. It has been noted in previous studies that a lack of anti-oxidants can put you at a higher risk for eye diseases such as macular degeneration.

Cataracts are cloudy areas that appear in the normally clear lens inside the eye. Usually, a clear lens allows light to pass through to the back of the eye, allowing the appearance of well-defined images. When a portion of the lens becomes nontransparent, light cannot pass through easily and a person’s vision becomes blurred. The cloudier the lens becomes, the worse the person’s vision will be.

Eye surgery to treat cataracts has annual costs of over $9 billion in the U.S. The total cost spent on services pertaining to vision problems is more than $20 billion.

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.”

Ercal and her investigators have long been experimenting with NACA regarding lead poisoning, HIV-related issues and other toxicities and have just recently started testing it on eye disorders.

Building upon previous research by her colleagues that questions if growth of cataracts can slow in rats by treatment with NACA, rats were first given L-buthionine-S,R-sulfoximine (BSO), a solution that causes cataracts to form. The NACA solution prevented cataracts from forming and will now be tested further to see if degeneration reversal is possible.

Ercal says further work in this area will help set up appropriate dosage and frequency, identify side effects, and other factors. With the use of animal subjects, the viability of human usage may become a reality.

Written by Kelly Fitzgerald