Stargardt's disease is an inherited condition that can severely impair a person's vision. Symptoms usually start to appear in late childhood or adolescence, and vision problems tend to persist throughout a person's lifetime. Stargardt's disease is classified as a type of juvenile macular dystrophy, meaning that it primarily affects the central focal point within the retina called the macula. Individuals who suffer from moderate to severe Stargardt's disease may need to wear prescription eyeglasses and use other low vision aids to maintain their quality of life.
In almost all cases, Stargardt's disease is caused by an inherited genetic defect. A gene called ABCA4 normally produces a protein that aids in focusing and converting light into impulses that can be interpreted by the brain. When a person inherits a mutated copy of ABCA4 from both parents, the vital protein may be defective or absent. As a result, light-capturing cells in the macula quickly degenerate and lead to vision loss.
Most people who are diagnosed with Stargardt's disease have average vision until about the age of six. Over the course of several years, their vision tends to progressively worsen as receptor cells die. Peripheral vision is usually left intact, but central vision becomes badly blurred. Since the macula also contains color-interpreting cells, the condition can cause significant difficulties distinguishing colors in the central vision. In severe cases, patients can become blind before the age of 20.
An ophthalmologist can usually diagnose Stargardt's disease by evaluating physical symptoms, asking about the nature of their onset, and microscopically inspecting the eye. Many different conditions, including direct injuries, can affect the eyes similarly to Stargardt's disease, so it is important to rule out all other possibilities when making a diagnosis. The doctor may be able to detect a lesion on the macula that is bordered by yellow flecks, remnants of defunct ABCA4 proteins. If the lesion appears infected, the ophthalmologist might decide to apply antibiotic eye drops and apply a protective bandage over one or both eyes.
There are no proven medical or surgical treatments for Stargardt's disease. Patients are usually fitted with eyeglasses or contact lenses to improve their central vision. Many people with the disorder are highly sensitive to light, so ultraviolet light-blocking sunglasses are recommended when going outdoors. In order to maintain independence, patients can make lifestyle adjustments such as reading big-type books and using voice recognition computer software. Increasing the amount of artificial light indoors and using a walking stick can also help to avoid accidents in the home.