Stargardt Disease

The information on this page is based on an interview with clinician-scientist Dr. Mark Penessi, linked above. 

What Is Stargardt Disease?

Stargardt is a genetic eye disease, with mutations in the ABCA4 gene. For this reason, it could also be called ABCA4 retinopathy. The mutation leads to a buildup of waste in the macula — the area of the retina that gives you sharp, central vision.

Patients usually have 2 mutations in this gene; they’ve inherited one from each parent.

Many times, when a patient is diagnosed, there is no known family history of Stargardt disease, because if you have only one copy of the gene, you don’t have the disease. When you inherit one mutation from each parent, it leads to Stargardt disease.

Common symptoms include dark spots in the central area of vision, light sensitivity, uncorrectable blurry vision, difficulty seeing fine details, challenges with light adjustment, poor night vision, color blindness, and lack of depth perception. Often, visual symptoms start in childhood, but the disease can also be first noticed and diagnosed in adults.

How Is It Diagnosed?

We strongly encourage everyone to get genetic testing these days—first and foremost to confirm the diagnosis made by an ophthalmologist. The ophthalmologist will look for yellowish flecks known as lipofuscin in the retina that are characteristic of the disease. However, other diseases can sometimes look similar to Stargardt disease clinically. Genetic testing can confirm what is seen clinically.

Genetic testing is very simple – most times, a saliva sample can be used. It usually takes 1 – 2 months to get results back.

Sometimes, a mutation isn’t found by testing, or only one copy of the mutation is found. The technology, and our interpretation of the results, is not perfect yet. In this case, if a patient presents clinically with Stargardt disease, but the test comes back negative, the test may be redone later on to see if a mutation was missed.

Tips for Healthy Vision

While no cure exists for Stargardt disease, there are several things that doctors recommend:

• Be cautious with vitamin A intake. The ABCA4 gene is responsible for vitamin A metabolism in the retina. Vitamin A is an important component of the visual cycle. But it is also the element that gets broken down into harmful waste products. So, very high doses of vitamin A could lead to faster progression of the disease. People should not avoid all vitamin A – you need some for normal metabolism. But, it’s advisable not to take more than the daily recommended allowance.
• Get lots of antioxidants and omega-3 fatty acids. While evidence that these are helpful for maintaining vision with Stargardt disease are somewhat limited, they are generally good for your health.
• Wear sunglasses when outside. Evidence shows that UV light can make visual degeneration worse; it won’t happen from one day at the beach, but it’s important to protect your eyes over your lifetime.
• Avoid smoking and secondhand smoke.

How Fast Will I Lose Vision?

A patient is their own best measuring stick when it comes to rate of visual degeneration. An ophthalmologist who specializes in inherited retinal degenerations (IRDs) can follow someone for 1.5 to 2 years to see what the change is and then make a prediction for the next 5 to 10 years. That’s the most accurate way to assess what might happen in the future. Looking at different patient averages is not always helpful; even siblings can have very different rates of visual degeneration.

What Treatments Are Out There?

While no cure for Stargardt disease currently exists, there are many different clinical trials going on for Stargardt disease right now, plus more in the pipeline, which is very exciting. The treatment field has exploded over the past couple of years. While many experimental therapies won’t make it to market, hopefully some of them will. It is possible that one day, gene therapy could halt the progression of the disease, and stem cells and optogenetics could even restore vision.

One way to find out about clinical trials is to visit an IRD specialist who will know about trials in your area. You can also go to clinicaltrials.gov and search for “Stargardt disease” to see what trials are happening nationally and even internationally.

What Else Should I Know? 

One of the great things about the internet is that it has allowed patients with rare diseases to find each other. Social media groups, patient organizations and non-profit eye organizations can all provide important means of support for people with Stargardt disease.

One thing that many patients want to know about is their ability to drive. Driving regulations differ by state, but one thing that could be a game changer for people with low vision is self-driving cars. Technology can help preserve and enhance independence, even when vision is lost. Another example is augmented reality glasses, which can do things like read a menu out loud to you and help you navigate your environment. Every day, more advances in technology are becoming available to help people with low vision maintain their active, independent lives.

Development of these resources was sponsored by: