New Treatment For Dry & Wet Macular Degeneration Shows Great Promise
At the University of North Carolina (UNC) School of Medicine, researchers in its Laboratory for Retinal Rehabilitation have been studying the potential of a class of drugs aimed at inhibiting MDM2 proteins that occur in the eyes of patients with age-related macular degeneration (AMD). Positve results in testing these inhibitors in mice models of the disease suggest a promising path to treatment of AMD, a disease that affects 11 million persons in the U.S. alone.
Macular degeneration is the result of damage to the retina, the part of the eye that creates the images we see. Debris begins to accumulate around the retina causing what is known as 'dry' AMD, and the visual impact is usually mild. But if the disease progresses to the 'wet' form of AMD, which happens in about 20 percent of the cases, the cause is abnormal blood vessels that leak fluid or blood into the eye resulting in major vision loss or blindness. (See image)
There is currently no common treatment for dry AMD, although embryonic stem cell therapy has been studied. There are a few treatments for wet AMD; the most effective treatment currently is called anti-VEGF, which targets the growth factors that lead to leaky blood vessels. MDM2 inhibitors work by activating a protein, p53, that initiates cell death, causing the regression of the abnormal blood vessels.
The new MDM2 inhibitor treatment would be given by injection, like anti-VEGF, but less frequently than anti-VEGF. MDM2 inhibitor treatment is less invasive than low-dose radiation, another treatment now in clinical trials. Researchers believe that the effects of MDM2 may be lasting.
"We believe we may have found an optimized treatment for macular degeneration," said senior author Sai Chavala, MD, director of the lab and assistant professor of cell biology and physiology at UNC. "... we'd like to have a long-lasting treatment so patients wouldn't have to receive as many injections." Additionally, the treatment would lower the treatment costs for AMD.