Stargardt Disease

Stargardt disease is an inherited retinal disease that causes progressive vision loss. It affects between 1 in 8,000 to 1 in 10,000 people (1). Central vision is usually affected first and symptoms are similar to age-related macular degeneration (AMD). Symptoms usually start in childhood or adolescence and because of this it is sometimes called juvenile or early-onset macular degeneration.

CAUSES

Stargardt disease affects the retina, the light-sensitive layer at the back of the eye. It mainly damages the macula, the small central portion of the retina that is responsible for detailed vision, such as reading, driving and recognizing faces.

The retina contains photoreceptor cells, which detect light and send signals to the brain to create images. There are two types:

Rods – help with night and peripheral (side) vision
Cones – control central and detailed vision

In Stargardt disease, both types of cells die, but cones are more affected. This can cause central vision loss, trouble seeing colors, and night blindness. The retinal pigment epithelium (RPE), a layer beneath the retina, is also damaged.

Stargardt disease is caused by gene mutations, which disrupt how eye cells function. About 95% of cases are due to mutations in the ABCA4 gene. Normally, the body uses vitamin A to create retinal cells. This process leaves behind lipofuscin, a fatty waste product. The ABCA4 gene helps remove excess lipofuscin. When ABCA4 is faulty, lipofuscin builds up, damaging photoreceptor cells.

In rare cases, Stargardt disease is caused by mutations in the genes ELOVL4, STGD4, or PRPH2.

GENETICS & INheritance

Stargardt disease is an inherited condition, meaning it is passed from parents to children. Everyone has two copies of each gene—one from their mother and one from their father.

Most cases of Stargardt disease are caused by mutations in the ABCA4 gene, which follows an autosomal recessive pattern. This means a person must inherit two mutated copies—one from each parent—to develop the disease. Parents who each carry one mutated copy are called carriers and do not have symptoms. If both parents are carriers, their child has a 25% chance of inheriting two mutated copies and developing Stargardt disease.

For more information about genes and how to get genetic testing in your province, please visit our genetic testing page.

Symptoms

Stargardt disease mainly affects central vision. Some side vision is usually maintained.

Symptoms include:

Loss of central vision in both eyes (may be uneven between eyes)
Difficulty distinguishing details and shapes
Blurry, black, or gray spots in the center of vision
Light sensitivity
Trouble adjusting to lighting changes
Color blindness (especially in later stages)

Symptoms usually begin in childhood or young adulthood, but some people don’t develop them until after age 45 (2). Vision loss can happen quickly or gradually, with earlier onset often leading to faster progression. or slow depending on individual factors. People who develop symptoms earlier often have faster vision loss. People with advanced Stargardt disease usually have a visual acuity between 20/70 and 20/200 (4). For more information on visual acuity, visit our “how the eye works” page.

DIAGNOSIS

To diagnose Stargardt disease, an eye doctor may perform several tests:

Eye exam: The doctor will use dilating drops to examine the retina. People with Stargardt disease have yellow spots under the macula, made of lipofuscin, which increase over time.
Fluorescein angiography: This test allows the doctor to see blood vessels in the eye and identify damaged areas. The doctor injects dye into a vein in the arm, which circulates through the body until it reaches the eye. The doctor will dilate the patient’s eye and then take a photo of the retina. People who have Stargardt disease will have a dark area in the retina (3). This test takes about 30 minutes, is safe and causes minimal discomfort.
Visual acuity test: The doctor will use several tools to measure how clearly a person can see. The eye doctor will also assess other symptoms such as colour blindness or light sensitivity.
Genetic testing: If the doctor suspects Stargardt disease they will use genetic testing to confirm the diagnosis by identifying mutations in genes linked to the disease.

Treatment & CARE

Currently, there are no treatments to cure or slow the progression of Stargardt disease.

Research shows that making certain lifestyle changes can have small to moderate effects in slowing the degeneration of photoreceptors.

Wear sunglasses and hats to protect against UV light. This may reduce lipofuscin buildup. You should use sunglasses that block 100% of UV light.
Avoid smoking and secondhand smoke, as smoking worsens retinal damage.
Limit vitamin A intake. Some research suggests that high doses of vitamin A may increase lipofuscin buildup. In a 2016 study, people with Stargardt disease who had lower vitamin A intake had better visual acuity than those with a higher intake. If you have Stargardt disease, speak with your eye doctor about your vitamin A intake (4).

research

Many research groups are working to develop new treatments for Stargardt disease. This includes treatments to reduce the symptoms causing vision loss, stop photoreceptor cell death, and even restore vision when it has already been lost.

Some of the most promising and exciting areas of research include:

Gene Therapy: The ABCA4 gene is too large for traditional gene therapy methods, but researchers are developing new ways to safely deliver the gene into retinal cells.
RNA Therapy: Instead of replacing the entire gene, this therapy modifies RNA to correct mutations in the ABCA4 gene before faulty proteins are made.
Drug Therapy: Scientists are testing drugs that could change how vitamin A is processed in the eye, reducing toxic buildup in the retina.
Optogenetics: This therapy helps people who have lost most of their photoreceptor cells. Special genes called opsins are injected into the eye to turn non-light-sensitive cells into light-detecting ones.
Stem cell therapy: Clinical trials are studying retinal cells made from stem cells to see if they can restore vision in people with retinal degenerative diseases like Stargardt disease.

Resources

Fighting Blindness Canada has developed resources to help you navigate vision care. Follow the links below to learn more.

Sign up for our e-newsletter to keep up to date on the latest breakthroughs and community events.
Contact our Heath Information line by email or phone to ask questions about your eye health.
Hear about the latest in vision research and connect with others at our View Point educational series
Learn about genetic testing and join our Inherited Retinal Disease Patient Registry to connect with clinical trials and treatments.
Discover more information on clinical trials for Stargardt disease
Learn more about all of Fighting Blindness Canada’s funded research.

References

Updated on March 3, 2025.

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