Stargardt disease is the most common inherited macular dystrophy in children and adolescents. The condition leads to a progressive loss of central vision, while peripheral vision is generally preserved. Because the macula (the area of the retina responsible for sharp vision) is affected, young patients often first notice difficulty reading or recognising faces.
In most cases Stargardt disease is caused by a mutation in the ABCA4 gene. This gene holds the blueprint for a protein that plays an important role in the metabolism of the visual pigment in the photoreceptors of the retina. If the protein is defective, toxic breakdown products (particularly lipofuscin) accumulate in the retinal pigment epithelium and damage the overlying visual cells.
The condition is usually inherited in an autosomal recessive manner: both parents carry one altered copy of the gene without being affected themselves. For each child there is a 25 % risk of developing the condition. More rarely there are also dominantly inherited forms, which are due to mutations in other genes (e.g. ELOVL4).
Stargardt disease usually begins between the ages of 6 and 20 with gradually increasing complaints:
Peripheral vision generally remains well preserved, so that spatial orientation and mobility are barely restricted.
There is currently no cure. Treatment aims to slow the course and to preserve quality of life:
Strong light can accelerate the deposition of lipofuscin. Wearing sunglasses with UV and blue light protection is recommended.
In contrast to other retinal conditions, patients with Stargardt disease should avoid high-dose vitamin A supplements, since excess vitamin A can increase the formation of lipofuscin.
Magnifying visual aids, special reading lamps, screen readers and electronic aids can make everyday life considerably easier. A low vision consultation helps in finding the right aids.
Intensive research gives grounds for hope: gene therapies aim to replace the defective copy of the gene. Stem cell based approaches seek to regenerate damaged cells. Drug treatments are intended to slow the deposition of lipofuscin. Clinical trials are running worldwide, and affected families can seek information about taking part.
Genetic counselling is highly advisable for affected families. It provides information about the pattern of inheritance, the recurrence risk for siblings and children, and current and future treatment options.
With the right support, children and adolescents with Stargardt disease can attend a mainstream school and lead an independent life. The following are important: