Stargardt's disease, also referred to as fundus flavimaculatus, is the most common strain of juvenile macular degeneration. This inherited disease results in gradual loss of vision -- at times leading to legal blindness. Inherited as an autosomal recessive trait, Stargardt's disease commences in late childhood and plateaus shortly afterwards, causing speedy reduction in visual ability. Approximately one out of every ten thousand children suffers from the disease, whose symptoms are similar to those of macular degeneration.
In patients, the disease can be diagnosed before age twenty, the time when reduced central vision is initially noticed. In the first stages, patients, though with adequate visual acuity, may experience difficulty trying to read in a dimly lit room. A cloudy vision due to blurry eyes and distortion of images are among other common symptoms of Stargardt's disease. Kids suffering from this disease usually start experiencing trouble adapting to darkness and impaired central vision between six and twelve years, though some symptoms are noticed in adulthood.
With the progression of Stargardt's disease, deposits rich in lipids begin to accumulate in the retinal pigment epithelium (RPE) layer that lies beneath the macula, a condition known as macula edema. The RPE layer is responsible for nourishing the photoreceptor cells. The development of the disease varies, but can be very rapid, reducing visual acquity to as low as 20/200 or 20/400 as recorded in about half of the patients. It is only in the latter stages of Stargardt's disease that color perception is impaired.
In 1997, research on the disease was launched. The ABCA4 gene, responsible for photoreceptor cells' nourishment, was isolated. The mutations in this gene that result in a cloudy vision were studied. The dysfunctional ABCA4 protein was noted to allow yellow lipids to accumulate on the RPE layer. Further research is dedicated to find out how the mutant gene alters the structure of the retina, leading to blurry eyes.
Patients suffering from Stargardt's disease can slow down its progression by putting on glasses that protect them from ultra-violet light and avoiding over-exposure to bright light. Misdiagnosing the disease, a common mistake, can result in scanty details being evident during eye examinations. More good news is that the disease never results in total loss of vision.
In addition, patients should be subjected to low vision care. Since they respond greatly to magnification, simple bifocals can be used in the very early stages. Later, CCTV systems are more useful. In school, large print materials should be made available to assist the children. Also recommended are eyewear with polycarbonate lenses to protect the eyes from any unexpected physical injury. Sport with fast moving projectiles must be avoided at all costs, unless the patients are provided with protective face shields.
With the medical industry embracing rapid technological changes, stem cell therapy is being tried out for treatment of Stargardt's disease. In late 2010, research commenced using retinal cells derived from human embryonic stem cells to see their success in treating patients with this disease.