A long-term study of patients receiving gene therapy shows positive results.[1.New England Journal of Medicine. Visual Acuity after Retinal Gene Therapy for Choroideremia by Robert Maclaren April 27, 2016DOI: 10.1056/NEJMc1509501] Researcher Dr. Robert Maclaren published a letter in the New England Journal of Medicine indicating that 5 out of the 6 patients with a rare genetic eye disease either improved or stayed the same after treatment. This may lead to approval of gene therapy for Choroideremia. This type of research may ultimately result in the approval of gene therapy for other more common eye diseases.
Men with Choroideremia have a defective gene that causes gradual and complete blindness. It is carried on the X chromosome. Only 1 in 50,000 males has the disease.[2. Choroideremia Research Foundation https://curechm.org] Choroideremia is diagnosed by a genetic test. There is no known cure.
However, these clinical trials offer hope for halting or reversing the Choroideremia. A virus delivers a normal copy of the gene causing Choroideremia into the eye. Only one eye in each patient was treated. The untreated eyes acted as “controls.” In all cases, the untreated eye continued to deteriorate.
One patient was unable to receive a full treatment due to surgical problems. His vision continued to deteriorate.
Two patients showed improvement after six months; the others stayed the same. Three to four years after the treatment, these two patients had continued their improvement. The three other patients maintained their visual acuity.
Some eye diseases have an obvious genetic component. Genetics may play a role in the risk of many eye disease. Ultimately, gene therapy may become the go-to remedy for various eye diseases, such as retinitis pigmentosa, Stargardt’s Disease, rod-cone dystrophy, optic nerve atrophy and macular degeneration.