Last year a study was led by Dr. Katherine A. High, Dr. Albert M. Maguire and Dr. Jean Bennett. The study enrolled 12 patients, 5 from the United States, 5 from Italy, and 2 from Belgium.

 All 12 patients had a disease called Leber’s congenital amaurosis. Leber’s congenital amaurosis is a rare inherited eye disease that appears at birth. Victims of the disease at born with impaired vision that deteriorates until the victim is totally blind. Leber’s congenital amaurosis can be caused by defects in 13 different genes. All 12 patients had a defect in the gene RPE65. RPE65 produces a vitamin A deteriorative that is crucial for the retina to detect light.

To treat the disease scientist used a method called gene therapy. Gene therapy is the process of injecting genes into an individuals cells or tissue to treat a disease.

Scientist began the process by cloning several good copies of the gene RPE65. The gene was then inserted in a defranged version of a human adenovirus [any group of DNA virus's that cause eye or respiratory diseases].

The engineered virus was then inserted into the patients retina. The virus then invaded the patients retinal cells and inserted the gene into the patients DNA. The cells that now had the gene could divide and replicate creating more cells with the good copy of RPE65.

Within a few weeks vision had improved for all the patients and they were able to perform daily tasks that they previously were unable to do.

Scientists hope they can use this same process to treat other diseases using different genes.