The New York woman was diagnosed at age 13 with the disease that causes light-processing cells to degenerate.
The implant -- a component of the Argus II Retinal Stimulation System by Second Sight Medical Products Inc. of Sylmar, Calif. -- stimulates retinal cells directly. The implant works with a tiny camera and transmitter -- mounted on a pair of sunglasses -- connected to a belt-worn wireless microprocessor and battery pack.
The system allows people who are functionally blind to begin to distinguish light from dark, visual patterns, or figures. This can help in distinguishing food on a plate and navigating in unfamiliar surroundings, the leader of the surgical team, Dr. Lucian Del Priore of New York- Presbyterian Hospital/Columbia University Medical Center, explained.
"In its current form, the device won't restore full visual function -- but if it dramatically reduces a patient's disability, that is a major advance," Del Priore said in a statement.
The surgery -- part of a clinical trial at six sites across the country -- is limited to people with retinitis pigmentosa because, unlike some other causes of blindness, this disease does not affect the inner layers of retinal cells that conduct electricity, Del Priore said.