Stargardt Disease Symptoms and How to Cope

An inherited disorder leading to vision loss in young people

Medically reviewed by Johnstone M. Kim, MD

Stargardt disease (or fundus flavimaculatus) is a type of juvenile macular degeneration that leads to vision loss in children and young adults. It affects about one in 10,000 children in the United States.

With Stargardt disease, there is an inherited genetic defect that causes the photoreceptors of the eye to die, with vision changes typically beginning between the ages of 6 and 12 years. It progresses until the impact on central vision (though not always peripheral vision) leads one to become legally blind.

This article explains Stargardt disease symptoms and why the inherited gene ABCA4 gene, a recessive gene, can lead to the disorder. It also discusses diagnosis and disease management.

What Stargardt Disease Looks Like

Stargardt disease affects a small area near the center of the retina called the macula. The macula is responsible for sharp central vision.

The symptoms of Stargardt are much like those of age-related macular degeneration (ARMD). The first symptom is decreased vision, with the following symptoms possibly following:

• Difficulty seeing in dim light

• Decreased sharp vision and close vision

• Tunnel vision (loss of peripheral vision)

• Poor color vision

• Detecting small blind spots

• Blurred vision and distorted vision

• Decreased dark adaption

• Light sensitivity

The most common symptom of Stargardt disease is the gradual loss of central vision in both eyes.

Different people will progress through the symptoms of the disease at different rates. Some people tend to have more rapid vision loss. Others may lose vision slowly at first, then worsen rapidly as it levels off. Most people with Stargardt disease eventually reach 20/200 vision, or worse.

Related: Macular Degeneration Facts and Statistics: What You Need to Know

Stargardt Disease and Genetics

Stargardt disease usually occurs from an inherited recessive gene, meaning both parents carry the gene that is expressed in their child. In most cases, it is caused by mutations in the ABCA4 gene though other genes (ELOVL4, PROM1) may be involved.

The ABCA4 gene contains a protein that clears away vitamin A byproducts inside the photoreceptors of the eyes. In cells that lack the protein, lipofuscin builds up and forms yellow clumps in the retina.

As the clumps of lipofuscin increase close to the macula, central vision becomes impaired. Over time, photoreceptors die and vision becomes further impaired.

Stargardt Disease Inheritance Pattern

If each parent carries the Stargardt gene mutation, their children have a 25% chance of inheriting the gene from each parent. They can be diagnosed with the condition even if parents don't have it. Rarely, a diagnosis can occur because of genetic changes in other genes or through a different Stargardt disease inheritance pattern (autosomal dominant rather than recessive).

Related: How Genetic Disorders Are Inherited

How Is Stargardt Disease Diagnosed?

An eye care professional may be able to diagnose Stargardt disease after a complete examination of the retina. Yellow spots in the retina, or lipofuscin deposits, can often be identified in the macula. The yellowish flecks appear in various shapes and sizes, usually in a ring-like pattern.

An eye doctor will use a variety of eye and vision tests to make a positive diagnosis of Stargardt disease. The following tests are helpful in assessing symptoms:

• Visual field testing: This is a measure of your central vision and is the most critical part of your vision. However, that is only one measure of your visual function. Another aspect is your overall visual field, sometimes referred to as peripheral vision. Although many people mistake it as simply a peripheral vision test, a visual field test is actually designed to measure the overall field of vision as it is interpreted by the brain in four neurological quadrants.

• Color testing: Loss of color vision is associated with Stargardt disease. The most common test for diagnosing color blindness is the Ishihara test. This quick and simple test consists of a series of pictures made up of colored dots. Among the dots is a figure, usually a number, made up of dots of a different color. A person with normal color vision will be able to see the number, but a color-blind person will see a different number or no number at all.

• Fundus photography: The word “fundus” is used to describe the inside or back of the eye. A photo of the fundus shows the center of the very back of the eye, or the retina. The optic nerve, macula, and main retinal blood vessels can all be seen in a typical fundus photo. Yellow spots, or lipofuscin, can be easily imaged with fundus photography for earlier Stargardt diagnosis.

• Optical coherence tomography (OCT): OCT is a noninvasive imaging technology used to obtain high-resolution cross-sectional images of the retina. OCT is similar to ultrasound testing, except that imaging is performed by measuring light rather than sound. OCT measures the retinal nerve fiber layer thickness in glaucoma and other diseases of the optic nerve.

• Electroretinography (ERG): ERG is an eye test used to detect the function of the retina, the light-detecting portion of the eye. The retina is comprised of layers of cells and photoreceptors, known as rods and cones. This test measures the electrical response of the light-sensitive cells in the eyes.

Stargardt Disease Treatment

No effective treatment for Stargardt disease exists. However, research is being done to look into possible therapies such as stem cell injections, gene therapy, and drug treatments.

If there appears to be blood vessel leakage or proliferation, the condition is often treated with intraocular injections, much like the treatments used to treat the "wet" variety of ARMD.

Research has found that UVA/UVB eye protection may slow the progression of this disease.

What Foods Should You Avoid With Stargardt Disease?

Some studies suggest that vitamin A used in excess can have harmful effects on the eyes of people with Stargardt disease but more research is needed. Supplementation should be avoided, although there is no need to avoid vitamin A in the diet.

Related: What Are Vitamin A and Carotenoids, and What Do They Do?

Coping With Vision Loss

If you are faced with the challenges of a Stargardt disease diagnosis, several services and devices are available to help.

Low vision aids can help people carry out daily activities and tasks, including handheld lenses, reading machines, and video magnification devices. All of these aids are geared toward maintaining independence.

Many people with Stargardt disease become visually disabled by their early 20s. The emotional impact of the disability can be significant, changing aspects of life like your employment and social life. Because of the great amount of support needed, counseling and occupational therapies tend to be part of the treatment plan.

Related: Living With Vision Loss

Summary

Stargardt disease is a type of macular degeneration that leads to vision loss in children and young people. It is caused by a genetic mutation that is inherited from parents.

Symptoms are similar to those of age-related macular degeneration, with vision loss that progresses from becoming light-sensitive or having blurred vision to total central vision loss in both eyes.

There is no cure for Stargardt disease, but adaptive tools and behaviors (like protecting the eyes from sunlight) are available to help manage symptoms. Research continues to explore treatment options.

Read the original article on Verywell Health.