Success in Treating Rare Eye Disease

On the fifth annual Rare Disease Day, the National Eye Institute (NEI), a part of the National Institutes of Health, joins patients and organizations around the world to raise awareness of rare diseases. In the United States, a disease is considered rare if it affects fewer than 200,000 Americans. Scientists have identified more than 7,000 rare diseases. Inherited gene defects account for 80 percent of rare diseases, many of which affect vision. NEI scientists have successfully used gene therapy to improve vision in people with Leber congenital amaurosis, a rare genetic disorder that causes blindness through the degeneration of photoreceptor cells—the rods and cones in the layer of tissue in the back of the eye called the retina. Gene therapy helps restore gene function by inserting copies of normal, functioning genes into cells. Read more.