Stargardt’s disease is a rare eye disorder, which is a type of inherited macular degeneration.
The partial or sometimes complete loss of vision associated with Stargardt’s disease is caused by the degeneration of photoreceptor cells in the central portion of the retina called the macula.
The retina is the delicate light-sensing tissue lining the inside wall of the back of the eye. Photoreceptor cells in the retina convert light into electrical signals, which are sent to the brain where they are processed to create the images as viewed by the eyes.
The macula, which is rich in cone photoreceptors, is responsible for sharp central vision, for tasks like reading, watching television, and looking at distant objects.
In Stargardt’s disease, the macula and retina are almost always irreversibly damaged, similar to instances of retinal detachment. Also Read: Seeing Floating Objects? Get Tested For Retinal Detachment
Stargardt’s disease typically develops during childhood or adolescence, but the age of onset and rate of progression can vary. Between ages 10 and 40, people with this condition usually start to develop symptoms. Issues can include trouble reading and color perception changes.
The central vision develops prominent blind spots in people suffering from Stargardt’s disease. This disease affects both eyes simultaneously.
Stargardt’s disease is a genetic abnormality that arises when a gene known as ABCA4 contains mutations in either one or both parents. In a minor set of cases, however, DNA aberrations in the gene ELOVL4 also triggers this eye condition.
This, in turn, can be inherited by the child, resulting in this complex visual ailment.
The primary indications of Stargardt’s disease consist of a gradual decline in visual abilities, such as:
- Inability to distinguish shapes
- Difficulty reading small-sized text
- Prominent yellow-coloured flecks in the retina
- Blurred vision of objects farther away as in the case glaucoma
- Problems with eye focus and maintaining a line of vision, such as in myopia Also Read: Myopia – Causes, Symptoms And Treatment
Initially, eye specialists examine the patient for more common forms of macular degeneration and perform the relevant diagnostic tests, including:
Back-of-eye examination to look for drusen and the spotted appearance it causes
Indocyanine green angiography to determine the exact type of macular degeneration a person has
Amsler grid testing to determine central vision abilities
Optical coherence tomography to get a better look at the retina
Once the doctor suspects Stargardt’s disease, the eyes of the patient are dilated, to probe the retina to see if there are elongated white, branching flecks present. If they are observed, the doctor will confirm the diagnosis of Stargardt’s disease using a procedure known as fluorescein angiography.
Fluorescein angiography involves injecting a fluorescent dye to highlight the blood vessels. For this specific test, the doctor observes the blood vessels at the back of the eye and records photos. Photos are taken before and after the dye is injected for comparison.
There is no cure or treatment for this condition. However, eye doctors or ophthalmologists often recommend that people wear sunglasses in the sun and areas where the light is bright, for it has been proven that UV-shielding glasses offer protective benefits.
In some cases, certain specific medications are injected intraocularly, to attempt to alleviate the vision impairment and other debilitating symptoms associated with this disease.