Researchers at the University of Pennsylvania School of Medicine have created the first animal model of age-related macular degeneration (AMD) caused by a mutation known to produce disease in people, an important first step in developing treatments.
The study appears in the October issue of Human Molecular Genetics.
Age-related macular degeneration is the most common cause of vision loss in elderly people, affecting more than 10 million people in the U.S. and about 50 million world-wide. Although it is a common and debilitating condition, prevention and treatment options are limited because AMD is a difficult condition to study.
“To better develop treatments for preventing the progression of AMD, we need to understand the real biochemical details of how AMD occurs,” says lead author Eric A. Pierce, MD, PhD, Associate Professor of Ophthalmology at Penn's K.M Kirby Center for Molecular Ophthalmology. “To do that, we need a model, and now we have one.”
AMD is a difficult condition to investigate because it develops late in life – patients typically show symptoms of AMD after 60, and the only samples researchers could use for study were from people who died while they had the early stages of AMD, and at that point, the tissue is not useful to study the condition's progression.
AMD is caused by the development of deposits between the retinal pigment epithelium and its basement membrane, called Bruch's membrane. The material starts as basal deposits and becomes drusen, extracellular deposits of protein and lipids that accumulate and can cause blindness. In order to prevent the basal deposits from forming, researchers need to understand the mechanisms that cause them to form in the first place.