Stargardt Disease

What is Stargardt disease?

Stargardt disease, also called Stargardt's disease or Stargardt macular dystrophy, is a genetic eye condition that causes progressive central sight loss. It's caused by progressive damage to the macula, which is a small area in the centre of the retina, and it affects detailed and colour vision.

The retina is the specialised light-sensitive layer that lines the back of the eye. The macula is the part of it which is responsible for our sharp, straight-ahead vision that we use for many activities – such as reading, recognising faces or watching TV.

What causes Stargardt disease?

Stargardt disease is usually caused by faults in a gene known as ABCA4. This gene provides the instructions for making an important protein that usually removes toxic by-products from the light-sensing cells (photoreceptors) in the retina at the back of the eye.

When this protein is missing or faulty, these substances build up and form a fatty waste product called lipofuscin. The fatty deposits in and around the macula start to affect central vision. Eventually, this causes progressive sight loss.

If faults in the ABCA4 gene are the cause of the condition, this means you will have inherited one faulty copy of the gene from each parent. The parents will typically each carry one copy of the faulty gene but will not have the disease themselves.

Although having faults in ABCA4 is the most common cause of Stargardt disease, it can be caused by faults in other genes –  ELOVL4, PROM1 and RDS (also known as PRPH2) – that contain instructions for making proteins involved in the retina.

What are the signs and symptoms of Stargardt disease?

The first sign of Stargardt disease is usually unclear or blurry vision, which you might notice as difficulty reading small print or seeing the signs in the distance. You may have difficulties in recognising colours, especially telling dark blue, brown and black apart, or orange and red.

As the condition progresses, things may start to appear distorted or wavy, and some people may also develop blind spots in the centre of their vision which progress and expand over time. Some people experience problems with light, such as sensitivity and difficulties adapting to low light levels.

Your central vision is affected first. Stargardt disease doesn’t normally affect other parts of the retina outside of the macula, so you'll usually maintain your side vision and won’t become completely blind.

The symptoms of Stargardt disease typically start in late childhood or adolescence and will gradually get worse over time. However, the age that the first symptoms develop and the speed of the disease progression varies widely from person to person. For some people, sight loss may not begin until later in adulthood. If it starts later in life it can sometimes be mistaken for age-related macular degeneration and a number of other conditions.

Is Stargardt disease serious?

Once the condition develops, symptoms will get slowly worse over time. As you'll usually maintain your peripheral (side) vision, it is rare to become completely blind, but most people with Stargardt disease will experience severe sight loss that affects their daily lives.

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How is Stargardt disease diagnosed?

A loss or change in central vision will usually lead to a diagnosis of Stargardt disease. An ophthalmologist (hospital eye doctor) will examine the retina at the back of the eye to look for characteristic yellowish flecks – lipofuscin deposits – in and around the macula.

These deposits are a fatty waste product that is a sign of the cells not working properly. They can vary widely in their size, number, colour and appearance. As the disease progresses, the flecks usually extend outward from the macula in a ring-like pattern.

You may also be asked to read standard eye charts, as well as other tests to assess sight loss. These include:

• Autofluorescence imaging (FAF) is a camera that can help identify lipofuscin deposits and areas of retinal damage
• Optical coherence tomography (OCT) is a scan to look for structural abnormalities in the layers of their retina
• Visual field testing – to check central and side vision
• Colour testing – to detect any loss of colour vision
• Fundus photo – to look at the retina in detail
• Electroretinography (ERG) – to test retinal function

Genetic testing is also available to help identify the genes involved in your Stargardt disease and provide information about the inheritance pattern and risks to other family members. By establishing a genetic diagnosis, this makes it easier to access the latest research and clinical trials that are relevant to your specific condition.

What are the treatments for Stargardt disease?

Unfortunately, there is currently no cure for Stargardt disease, and very little can be done to slow down its progression. However, there is a lot of ongoing research into potential new treatments, including gene, stem, and drug therapies.

Ultraviolet (UV) rays are believed to worsen the macular degeneration in Stargardt disease. Using ultraviolet screening sunglasses outdoors, along with hats or caps is recommended for people with the condition or at high risk of it – even if you use the prism and telescopic glasses.

What can help Stargardt disease?

There are lots of things that can help someone with Stargardt disease to make the most of their remaining vision, such as magnifiers, brighter lighting, and using colour to make things clearer to see. You may also benefit from assistive technologies, such as text-to-speech software.

Evidence suggests that people with the condition should avoid taking vitamin A supplements as this may help promote the accumulation of lipofuscin and the premature ageing process in the retina. If you would like more information this should be discussed with your clinician.

An assessment with a low vision specialist can help identify what will help you. If you're concerned about how Stargardt disease may affect other family members, you can access genetic testing along with support from a genetic counsellor who can help you to make informed medical and personal decisions.

Have your eyes tested every two years even if you think your vision is fine. An eye test can spot some eye conditions and, if caught early, treatment may prevent further deterioration.

Fight for Sight's Research Strategy has pledged to spend over 20 million on pioneering eye research over the next five years.

If you're personally affected by Stargardt disease and are interested in fundraising to help us fund cutting-edge research in this area find out how to set up a family fund.