April 2, 2013 – By Jim Dryden
A new study raises the intriguing possibility that drugs prescribed to lower cholesterol may be effective against macular degeneration, a blinding eye disease.
Researchers at Washington University School of Medicine in St. Louis have found that age-related macular degeneration, the leading cause of vision loss in Americans over 50, shares a common link with atherosclerosis. Both problems have the same underlying defect: the inability to remove a buildup of fat and cholesterol.
The new study is published online in the journal Cell Metabolism.
PHOTO APTE LABORATORY
Beneath the retina of a patient with macular degeneration,
the small light dots against the orange background are
cholesterol deposits, and as cholesterol builds up, the area
becomes inflamed, spurring the development of abnormal
blood vessels that can lead to loss of vision.
Working in mice and in human cells, the researchers shed new light on how deposits of cholesterol contribute to macular degeneration and atherosclerosis and even blood vessel growth in some types of cancer.
Patients who have atherosclerosis often are prescribed medications to lower cholesterol and keep arteries clear. This study suggests that some of those same drugs could be evaluated in patients with macular degeneration.
“Based on our findings, we need to investigate whether vision loss caused by macular degeneration could be prevented with cholesterol-lowering eye drops or other medications that might prevent the buildup of lipids beneath the retina,” says senior investigator Rajendra S. Apte, MD, PhD.
The new research centers on macrophages, key immune cells that remove cholesterol and fats from tissues. In macular degeneration, the excessive buildup of cholesterol begins to occur as we age, and our macrophages begin to malfunction.
In the “dry” form of age-related macular degeneration, doctors examining the eye can see lipid deposits beneath the retina. As those deposits become larger and more numerous, they slowly begin to destroy the central part of the eye, interfering with the vision needed to read a book or drive a car.