What are the symptoms? People affected by Stargardt macular dystrophy experience to varying degrees: decreased central vision, which gets worse over a period of months and yearsproblems with tracking objects and readingloss of colour visiongradual loss of ability to distinguish facesreduced ability to see clearly. What are the causes? The cause of Stargardt macular dystrophy is a defect in a gene called ABCA4 (originally called ABCR) which causes progressive dysfunction and loss of special cells called cone photoreceptors, from the central part of the retina. Cone cells ensure clear central vision, colour perception, and the ability to see fine detail. The other visual cells in the outer areas of the retina, which are called rods, remain unaffected and peripheral (side) vision is usually preserved in most affected people. How is it diagnosed? A diagnosis of Stargardt macular dystrophy is made after examination by a specialist in retinal diseases. OCT (optical coherence tomography) and AF (autofluorescence imaging) are carried out, which are special pictures of the eye are taken after dilating the pupil with drops. These are standard, painless procedures in most specialist eye clinics. A further test, known as an electroretinogram (ERG), is often done to determine the extent of the retinal dysfunction and gives clues about prognosis (how the condition might progress). The ERG measures the electrical response of the eye’s light-sensitive cells. Electrodes are placed over the lower eyelid or on the skin near the eye to measure the electrical currents coming from the cells when a light is flashed and observed by the patient. How is it treated? At present there is no cure for Stargardt macular dystrophy, although drug treatments, gene-replacement and cell-transplantation techniques are being worked on. Management involves providing magnification and conditions of high-contrast and reverse-contrast (bright detail on a darker background). Computers, E-readers (eg Kindle) and tablets are useful in this regard. Smoking, which is a risk-factor in age-related macula disease, is also discouraged in Stargardt disease. A healthy diet is important, but there are no proven benefits of vitamin supplementation. Evidence from suggests that vitamin A supplementation and excessive light on the retina (direct sunlight for example) might actually exacerbate the disorder. The light from monitors, or indoor lights, is not likely to matter. Inheritance patterns and prenatal diagnosis Inheritance patternsThe condition is always autosomal recessive. This means that the disorder is rarely transmitted to children from an affected parent unless the parent is married to a close relative. Carrier testing is not generally available nor offered to unrelated partners of affected persons in the UK. Prenatal diagnosisPrenatal diagnosis for a family wanting a child after diagnosis in an existing child is possible, if the molecular diagnosis has been determined. For advice on these issues it is recommended the couple be referred to their Clinical Genetics department by their GP. Is there support? Stargardt Support Group Tel: 0161 792 7392Email: firstname.lastname@example.org The Group is a small, informal network, established in 1995. It offers a listening ear and linking where possible. Group details last updated September 2014. Macular Society Helpline: 0300 3030 111Email: email@example.comWebsite: macularsociety.org The Society is a Registered Charity in England and Wales No. 1001198. It provides information and support for people with macular conditions, and their families and friends. The Society runs support groups across the UK, and offers a range of services including counselling and telephone befriending. Group details last updated February 2016.