Silicon chip retinal implants show early signs of success

The two men and one woman, who had lost almost all their vision because of retinitis pigmentosa, are between 45 and 75 years of age. Surgeons from the University of Illinois at Chicago Medical Center operated on two patients last month. A third patient received an implant at Central DuPage Hospital, in Winfield, Illinois. Preliminary tests have shown no complications but it will be several weeks before conclusive results can be seen. The silicon microchip is one-tenth of an inch in diameter and thinner than a human hair. It contains 3,500 microscopic solar cells that convert light into electrical impulses. Its purpose is to replace damaged photoreceptors. The self-contained Artificial Silicon Retinas (ASR) require no batteries or wires because they are powered by light that enters the eye. Doctors hope the implants will stimulate the retina to develop some vision. Illinois-based Optobionics Corporation developed the ASR after president and CEO Dr Alan Chow and his brother Vincent, vice-president of engineering, invented it. The surgical team for the two-and-a-half hour operations was Dr Chow, Dr Gholam Peyman, professor of ophthalmology and co-director of vitreoretinal surgery at Tulane University Medical Center, and Dr Jose Pulido, head of ophthalmology and visual sciences at the University of Illinois at Chicago.