diagnosis of choroideremia can be made based on family history, symptoms and the characteristic appearance of the fundus. However, choroideremia shares several clinical features with retinitis pigmentosa, a similar but broader group of retinal degenerative diseases, making a specific diagnosis difficult without genetic testing. Because of this choroideremia is often initially misdiagnosed as retinitis pigmentosa. A variety of different genetic testing techniques can be used to make a differential diagnosis. Management While nothing currently can be done to stop or reverse the retinal degeneration, there are steps that can be taken to slow the rate of vision loss. UV-blocking sunglasses for outdoors, appropriate dietary intake of fresh fruit and leafy green vegetables, antioxidant vitamin supplements, and regular intake of dietary omega-3 very-long-chain fatty acids are all recommended. One study found that a dietary supplement of lutein increases macular pigment levels in patients with choroideremia. Over a long period of time, these elevated levels of pigmentation "could" slow retinal degeneration. Additional interventions that may be needed include surgical correction of retinal detachment and cataracts, low vision services, and counseling to help cope with depression, loss of independence, and anxiety over job loss. Gene therapy Gene therapy is currently not a treatment option, however human clinical trials for both choroideremia and Leber's congenital amaurosis (LCA) have produced somewhat promising results. Clinical trials of gene therapy for patients with LCA began in 2008 at three different sites. In general, these studies found the therapy to be safe, somewhat effective, and promising as a future treatment for similar retinal diseases. In 2011, the first gene therapy treatment for choroideremia was administered. The surgery was performed by Robert MacLaren, Professor of Ophthalmology at the University of Oxford and leader of the Clinical Ophthalmology Research Group at the Nuffield Laboratory of Ophthalmology (NLO). In the study, 2 doses of the AAV.REP1 vector were injected subretinally in 12 patients with choroideremia. There study had 2 objectives: to assess the safety and tolerability of the AAV.REP1 vector to observe the therapeutic benefit, or slowing of the retinal degeneration, of the gene therapy during the study and at a 24-month post-treatment time point Despite retinal detachment caused by the injection, the study observed initial improved rod and cone function, warranting further study. In 2016, researchers were optimistic that the positive results of 32 choroideremia patients treated over four and a half years with gene therapy in four countries could