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 pointDespite 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 be long-lasting. Preimplantation genetic diagnosis
For women who carry a mutation in the CHM gene, preimplantation genetic diagnosis can be used during the in-vitro fertilization process to select unaffected embryos to implant. This process call be applied to any monogenic disease. Other potential therapies
While choroideremia is an ideal candidate for gene therapy there are other potential therapies that could restore vision after it has been lost later in life. Foremost of these is stem cell therapy. A clinical trial published in 2014 found that a subretinal injection of human embryonic stem cells in patients with age-related macular degeneration and Stargardt disease was safe and improved vision in most patients. Out of 18 patients, vision improved in 10, improved or remained the same in 7, and decreased in 1 patient, while no improvement was seen in the untreated eyes. The study found "no evidence of adverse proliferation, rejection, or serious ocular or systemic safety issues related to the transplanted tissue."
The first symptom many individuals with choroideremia notice is a significant loss of night vision, which begins in youth. Peripheral vision loss occurs gradually, starting as a ring of vision loss, and continuing on to "tunnel vision" in adulthood. Individuals with choroideremia tend to maintain good visual acuity into their 40s, but eventually lose all sight at some point in the 50–70 age range. A study of 115 individuals with choroideremia found that 84% of patients under the age of 60 had a visual acuity of 20/40 or better, while 33% of patients over 60 years old had a visual acuity of 20/200 or worse. The most severe visual acuity impairment (only being able to count fingers or worse) did not occur until the seventh decade of life. The same study found the mean rate of visual acuity loss to be about 0.09 logMAR per 5 years, which is roughly 1 row on a Snellen chart. Diagnosis
A 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.