The idea of using contact lenses that contain medicine to treat eye diseases such as glaucoma is not new. A major hurdle in the technology, however, has been finding a way to keep tears from washing away the medicine too quickly.
Anuj Chauhan, PhD, and colleagues may have found the answer — vitamin E. The researchers say that incorporating the antioxidant vitamin into the therapeutic contact lens makes the glaucoma medicine last almost 100 times longer than it does with current drug-eluting contacts.
Many ophthalmologists and optometrists feel medicine-containing contact lenses may solve a major problem in glaucoma treatment. Traditionally, eye drops have been used to apply glaucoma medicine to the eye. But many patients forget to use their drops as directed, which can cause the condition to progress, leading to serious vision loss, even blindness.
And even when eye drops are used as directed for glaucoma treatment, they often are not as effective as they should be. Some studies suggest that only about 1 to 5 percent of the applied drug reaches the target tissue in the eye, and the rest is distributed throughout the body by the circulatory system, possibly causing side effects.
Many eye doctors and glaucoma experts say the use of medicated contact lenses may eliminate these problems, leading to more effective glaucoma treatment.
A second possible benefit of adding vitamin E to medicine-containing contact lenses is that the vitamin may help prevent cataracts due to its antioxidant activity, according to the researchers. Vitamin E also blocks UV radiation, possibly leading to reduced eye damage from UV light.
Though the new vitamin E therapeutic contact lenses are not yet approved by the FDA, animal studies in beagle dogs are ongoing to determine the effectiveness of the lenses in treating glaucoma.
SOURCE: Contact lenses loaded with vitamin E may treat glaucoma. (Press release issued by the American Chemical Society, March 24, 2010.)