In surprise result, gene therapy reverses blinding eye disease

This is the same technique used to create GMO crops.

http://www.nbcnews.com/health/surprise-result-gene-therapy-reverses-blinding-eye-disease-2D11934179

Maggie Fox NBC News
Jan. 15, 2014

An experimental therapy for a blinding eye disease showed early – and surprising – promise when it improved the vision of patients in an early trial that was only supposed to test its safety, doctors reported Wednesday.

The experimental gene therapy not only stopped the steady degeneration of the patients’ vision, but appears to have reversed some of the damage. And the effects have lasted two years in one case, British researchers report in the Lancet medical journal.

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“It is still too early to know if the gene therapy treatment will last indefinitely, but we can say that the vision improvements have been maintained for as long as we have been following up the patients, which is two years in one case,” says Dr. Robert MacLaren of the Nuffield Laboratory of Ophthalmology at the University of Oxford, who leads the research team.

“In truth, we did not expect to see such dramatic improvements in visual acuity and so we contacted both patients’ home opticians to get current and historical data on their vision in former years, long before the gene therapy trial started. These readings confirmed exactly what we had seen,” he added in a statement.

The men taking part in the trial all have choroideremia, a genetic disease that causes vision to start breaking down when patients are still children. The defective gene, called CHM, is on the x chromosome, so it almost exclusively affects males – females have an extra x chromosome that usually makes up for any lost function. It causes about 4 percent of all cases of blindness, according to the National Institutes of Health.

The condition breaks down various parts of the retina, the reflective tissue at the back of the eye that collects light and images. The gene therapy approach uses a virus to carry a corrective gene directly into the retina.

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