Altering eye cells may one day restore vision

Doctors may one day treat some forms of blindness by altering the genetic program of the light-sensing cells of the eye, according to scientists at Washington University School of Medicine in St. Louis.

Working in mice with retinitis pigmentosa, a disease that causes gradual blindness, the researchers reprogrammed the cells in the eye that enable night vision. The change made the cells more similar to other cells that provide sight during daylight hours and prevented degeneration of the retina, the light-sensing structure in the back of the eye. The scientists now are conducting additional tests to confirm that the mice can still see.

“We think it may be significantly easier to preserve vision by modifying existing cells in the eye than it would be to introduce new stem cells,” says senior author Joseph Corbo, MD, PhD, assistant professor of pathology and immunology. “A diseased retina is not a hospitable environment for transplanting stem cells.”

The study is available in the early online edition of Proceedings of the National Academy of Sciences.

Mutations in more than 200 genes have been linked to various forms of blindness. Efforts are underway to develop gene therapies for some of these conditions.

Rather than seek treatments tailored to individual mutations, Corbo hopes to develop therapies that can alleviate many forms of visual impairment. To make that possible, he studies the genetic factors that allow cells in the developing eye to take on the specialized roles necessary for vision.