Choroidal Dystrophy is actually the name given to a group of conditions, the most common of which is central areolar choroidal dystrophty. This condition tends to affect vision starting in the teen years and through the 4th decade of life. The loss of vision varies greatly between affected patients. Many studies have been performed in order to locate the genes affected in this condition. It has been shown that this condition is autosomal dominant, meaning that often several members of a particular family can be affected by the condition in every generation.
Initially, this condition can mimic Stargardt's disease. However, later it can be distinguished by its particular appearance in the macular region of the retina. Given the genetic nature of this disease, it is unclear if oral supplemts would help in diminishing the effects of this condition. Some have tried antioxidant and zinc supplementation, but again the benefit of this is not clearly evident.
Unfortunately, there are no curent transplantation techniques that would help. Also, as mentioned above, most studies have been geared towards finding the genes responsible for the disease. As of this date, there does not appear to be any clinical trials examinig different treatment possibilities.
It is important for patients suffering from this condition to find a good low-vision eye specialist that can help optimize the vision the patient does have. The vision is never completely lost, and peripheral vision remains normal. There are many aids that can help patients with such a choroidal disease.
I wish I could provide a brighter outlook. Unfortunately, there are still many genetic diseases for which we have very few answers as ophthalmologists. I wish you the best of luck as you help this patient during the difficult adjustment to low vision.