Stargardt disease is a hereditary condition that leads to blurry or distorted central vision. Symptoms generally emerge between ages 6-20 and typically affect both eyes.

Eye doctors can usually identify Stargardt disease during a dilated eye exam by noting elongated, white branching flecks on the retina made up of lipofuscin which obscures fluorescein from being seen by the camera.

Symptoms

Stargardt disease affects the retina (the light processing tissue lining the inside of your eye). It usually starts in the macula at the center of your retina, where rods and cones have their highest concentration for sharp central vision. Over time, people living with Stargardt may slowly lose central vision gradually resulting in difficulty reading as well as gray or black spots appearing at their field of vision due to deposits of an abnormal fatty substance called lipofuscin which makes distinguishing objects difficult as well as distorting vision altogether.

Stargardt disease symptoms may not be severe, yet they can make driving or using the computer difficult and interfere with daily activities. More advanced forms may cause loss of color vision and difficulty seeing in low lighting environments; typically its progression leads to legal blindness (defined by an eye chart score of 20/200 or lower).

Stargardt disease results from mutations to the ABCA4 gene, which normally produces a protein to remove any leftover fatty substances after using vitamin A to make retinal cells. Unfortunately, Stargardt disease prevents it from producing this protein, leading to an accumulation of these deposits on retina.

People with Stargardt disease can be identified through a regular eye exam and additional diagnostic techniques, including pupil dilation using special eye drops and retina examination. Macula will usually look normal initially; however in those suffering from Stargardt disease yellow flecks will appear within days. An imaging technique called optical coherence tomography (OCT) may also be employed which takes cross-sectional pictures of the retina for additional testing purposes.

Genetic testing is available to people who have a family history of Stargardt disease and want to find out whether they carry the gene that causes it, as it could give an accurate indication if you carry one and pass it along to your children, who then have a 50% chance of inheriting and developing Stargardt themselves.

Diagnosis

Stargardt disease is an inherited eye condition causing progressive vision loss, affecting the macula – an area of retina responsible for central, clear vision. People affected by Stargardt have an accumulation of lipofuscin in retinal cells responsible for processing light images into visual images resulting in blurriness along straight lines, difficulty seeing details at distance, difficulty distinguishing colors and making sense of patterns seen.

Ophthalmologists can accurately diagnose this disease during a comprehensive eye exam. Your pupils will be dilated with special drops so your eye doctor can more thoroughly examine them, while looking out for any yellow flecks characteristic of the condition.

At an eye exam with IALVS, the doctor will ask questions about your family history of vision problems as well as any symptoms you are experiencing with your own eyes. If genetic changes are detected, genetic testing could be suggested in order to pinpoint which gene(s) cause Stargardt disease.

An electroretinogram (ERG) is a test designed to measure the electrical responses of your retina when light is flashed onto it, producing electric impulses which are recorded by electrodes on your face. ERG results provide insight into any abnormal functions in your retina or damage to its macula that might exist.

Fluorescein angiography, which detects a bull’s-eye pattern behind the eye; and fundus autofluorescence are other tests for Stargardt disease that may reveal its signs and symptoms. Some of these flecks appear hyperautofluorescent during early stages of disease progression; others become increasingly visible over time, surrounded by rings of decreased autofluorescence which become more noticeable as disease advances. Stargardt’s disease typically appears during childhood or adolescence; however, adulthood is also possible. Most often caused by mutations to the ABCA4 gene that are passed along autosomally recessively; however, another form involving dominant mutations to ELOVL4 genes also exists, producing similar symptoms to typical Stargardt’s.

Treatments

Stargardt disease cannot be cured, but there are treatments available to help manage vision loss. An IALVS eye doctor will conduct a comprehensive eye exam and recommend helpful low-vision devices and rehabilitation to ensure you make the most out of what vision remains.

At your exam, an ophthalmologist will check the health of both of your eyes, suggesting genetic testing to identify whether you possess the gene mutation associated with Stargardt disease. They may also ask about family histories for any vision issues.

Stargardt disease results from genetic mutations that accumulate a toxic waste product known as lipofuscin in retinal cells known as retinal pigment epithelial (RPE) cells – cells responsible for feeding light-sensitive photoreceptors in your eye – known as RPE cells. When this waste accumulates, it prevents RPE cells from functioning normally, leading to progressive loss of central and high-resolution vision.

Scientists are exploring various treatments for Stargardt disease, such as gene and drug therapy. One promising study involves injecting healthy versions of ABCA4 gene that control production of protein defective in people with Stargardt disease directly into retinal cells to restore production of normal protein and reduce accumulation of lipofuscin.

Animal studies have demonstrated that lentiviral gene transfer of ABCA4 effectively reversed the Stargardt phenotype in abca4 knockout mice, as well as reduced lipofuscin build-up within retinal cells.

Researchers from the National Institutes of Health have discovered that mutations of ABCA4 gene inhibit cells responsible for producing and transporting retinaldehyde – an essential substance needed for light to electrical signals conversion in the eye – thus leading to loss of vision associated with Stargardt disease. This discovery sheds new light on why genetic mutations contribute to Stargardt.

Fluorescein angiography can often be used to detect Stargardt disease. During this test, dye is injected into one arm and photographs taken of the retina – in Stargardt disease this results in yellow-tinged lipofuscin build-up on its surface that can be seen through yellow flecks on it.

Frequently Asked Questions

Stargardt disease is a progressive eye condition that gradually reduces an individual’s ability to see fine details and objects clearly, specifically central vision; peripheral (side) vision remains unaffected. Early signs may include black, grey or hazy spots in your field of vision that take longer for your eyes to adjust between light and dark environments as well as loss of color blindness in later stages.

Stargardt disease cannot be cured, but there are low vision aids that can help make the most of what vision remains. You may benefit from magnifiers, reading glasses and video monitors to assist with daily tasks; prescription sunglasses that block UV rays to protect eyes from further damage may also help. Ophthalmologists advise wearing dark sunglasses when outside in bright sunlight in order to decrease lipofuscin build-up while smoking is also best avoided and secondhand smoke exposure should also be avoided.

If you suspect Stargardt disease, contact Dr. Armstrong from Low Vision Optometry in Roanoke, VA immediately for genetic testing to diagnose it and a consultation regarding treatment options available to improve quality of life.

Stargardt disease is most frequently caused by mutations to the ABCA4 gene. There is a small chance that both parents carry the mutation, while some have only one parent affected by it. If your family history includes Stargardt disease, it would be wise to seek genetic counseling as soon as possible so as to determine your chances of passing it onto future generations.

Nanoscope Therapeutics’ experimental drug MCO-010, being developed for Stargardt disease treatment by Nanoscope Therapeutics and given FDA Fast Track and Orphan Drug designation, has begun clinical trials as an anti-Stargardt agent. An early study with six Stargardt patients treated with MCO-010 saw an average improvement in best corrected visual acuity of 5.5 letters while experiencing 15 letters improvement on perimetry test scores.