After reading the information below, click here to learn more about POB’s programs for people with Stargardt’s Disease.
What is Stargardt’s Disease?
Stargardt’s is the most common form of inherited juvenile macular degeneration. People with Stargardt’s Disease lose central vision (what they see when they look straight ahead), but keep their side (peripheral) vision. Stargardt’s Disease most commonly affects children and young adults.
The disease is usually diagnosed when individuals under age 20 notice vision loss. A person’s retina with Stargardt’s Disease has a macular lesion surrounded by yellow-white spots with irregular shapes. The macula is in the center of the retina and is responsible for the fine, detailed central vision that is lost.
Among people with Stargardt’s Disease, vision loss is varied. One study of 95 individuals with Stargardt’s showed that once a visual acuity of 20/40 was reached, there was often rapid vision loss until acuity was reduced to 20/200, or legal blindness.
By age 50, approximately 50% of all those studied had visual acuities of 20/200 or worse. Eventually, almost all individuals with Stargardt’s Disease are expected to have visual acuities in the range of 20/200 to 20/400. This vision loss cannot be corrected with eyeglasses or contact lenses. In the late stages of the disease, there may also be a noticeable impairment of color vision.
Causes
Mutations in a gene called ABCA4 are the most common cause of Stargardt’s Disease. This gene makes a protein that usually clears away Vitamin A byproducts inside photoreceptors, which are light-sensing cells inside of the retina. Cells that lack the ABCA4 protein accumulate clumps of lipofuscin, a fatty substance that forms yellowish flecks. As the clumps of lipofuscin increase in and around the macula, central vision becomes impaired. Eventually, these fatty deposits lead to the death of photoreceptors, and vision becomes further impaired.
Symptoms
The most common symptom of Stargardt’s Disease is a slow loss of central vision in both eyes. People with the disease might notice gray, black, or dull spots in the center of their vision, or that it takes longer than usual for their eyes to adjust when moving from light to dark environments. Their eyes may be more sensitive to bright light. Some people also develop color blindness at later stages of the disease.
Risk Factors
Stargardt’s Disease is passed on to a child via two parents carrying the recessive gene, where each parent has a recessive Stargardt’s Disease gene paired with a normal gene. Children of two carriers have a 25% chance of inheriting the disease.
Treatment
Currently, there is no treatment for Stargardt’s Disease. Some eye doctors encourage people with Stargardt’s Disease to wear dark glasses and hats when out in bright light. Cigarette smoking and second-hand smoke should be avoided.
Many services and devices can help people with Stargardt’s Disease carry out daily activities and maintain their independence, including low vision rehabilitation.
