German company Retinal Implant on Wednesday unveiled preliminary, yet quite promising, results from a four-year study of 11 patients who underwent retinal-implant surgery after losing their sight due to retinitis pigmentosa.
The company's implants were not the first artificial retina surgically inserted into human patients, and other studies have shown that implants can help a blind person see light and the outlines of objects, the company acknowledges.
But Retinal Implant's clinical trial, it said, gave all 11 patients the ability to see well enough to read or recognize foreign objects. One patient was so thrilled with the results, the company added, that he refused to have the implants removed after the study's one- or three-month testing period, and he reports continued success four years later.
Retinal Implant's subretinal implants, it described in a statement, place the chip in the macular region, beneath the retina:
The macular region is believed to be the ideal location because this is the most sensitive area, which is responsible for producing clear images in sighted people. By placing the chip below the retina, the natural way of processing light--through the pupil of the eye to the retina to the optical nerve and finally to the brain--can be restored.
"We learned a great deal between our first and last patient, especially from patient 10 to 11," says Dr. Walter-G. Wrobel, president and CEO of Retina Implant. "The 11th/last patient in the study was the only one to have the chip placed exactly in the macular region, and he was able to see more clearly than any other patient in the trial. Additionally, every patient tolerated the surgery well; no adverse events occurred."
RP is estimated to afflict some 200,000 people worldwide and is a progressive disease with no known cure. As such, retinal implants hold, at this point, the greatest promise for those suffering from the genetic disease to regain sight.
Retina Implant is presenting results of this clinical trial at the Association for Research in Vision and Ophthalmology annual meeting May 2 to 6 in Fort Lauderdale, Fla.