Surgeons have carried out the first operations in Britain using a pioneering “bionic eye” that could in future help to restore the sight of the blind.
Two successful operations to implant the artificial electronic device into the eyes of two blind patients were conducted last week at Moorfields Eye Hospital in London, it emerged today.
The device — the first of its kind in the world — incorporates a video camera and transmitter mounted on a pair of glasses.
This is linked to an artificial retina, which transmits moving images along the optic nerve to the brain, and enables a patient to discriminate rudimentary images of motion, light and dark.
The operations at Moorfields were conducted as part of an international clinical trial of the technology, known as the Argus II retinal implant, which has already proved successful in restoring rudimentary vision to blind patients with common causes of sight loss such as age-related macular degeneration (AMD) and retinitis pigmentosa.
American researchers are now hoping to develop a camera to the size of a pea, such that it might also be implanted within the eyeball, effectively replacing natural tissue with artificial technology.
Surgeons hope this implanted version of the technology could be available to NHS patients within three to five years.
The Argus II device uses a video camera to capture images, which are converted into electrical signals and then transmitted wirelessly to the implant behind the retina.
The electrodes in the implant unscramble the signal to create a crude black and white picture, which is relayed along the optic nerve to the brain. The brain can then perceive patterns of light and dark spots corresponding to which electrodes are stimulated.
Mark Humayun, professor of ophthalmology and biomedical engineering at the Doheny Eye Institute in Los Angeles, California, which developed the technology, said yesterday: “The camera is very, very small, and very low power, so it can go inside your eye and couple your eye movement to where the camera is.
“With the kind of missing information the brain can fill in, this field is really blossoming.
“So in the next four to five years I hope, and we all hope, that we see technology that’s much more advanced.”
Linda Moorfoot is one of a few American patients to be fitted with the current version of the implant. She had been totally blind for more than a decade with the inherited condition retinitis pigmentosa.
But, with the aid of the camera mounted on a pair of sunglasses, she can now see a rough image of the world made up of light and dark blocks.
She told Sky News: “When I go to the grandkids’ hockey game or soccer game I can see which direction the game is moving in. I can shoot baskets with my grandson, and I can see my granddaughter dancing across the stage. It’s wonderful.”
Ms Moorfoot’s implant has just 16 electrodes but the US surgeons have helped to fit an even more advanced device to the two British patients.
The updated model has 60 electrodes to give a clearer image. Meanwhile in California, scientists are developing an implant with 1,000 electrodes, which should allow facial recognition.
The identities of the British patients have been concealed while doctors monitor their progress.
Lyndon da Cruz, consultant retinal surgeon who carried out the operations with his team, said: “Moorfields is proud to have been one of only three sites in Europe chosen to be part of evolving this exciting new technology. The devices were implanted successfully in both patients and they are recovering well from the operations.
“It is very special to be part of a programe developing a totally new type of treatment for patients who would otherwise have no chance of visual improvement.”
John Marshall, of St Thomas’ Hospital, London, and the British Retinitis Pigmentosa Society (BRPS), gave warning that it was still “very early days” for the technology.
He said: “It is very, very good news that devices have been developed, it is very good news that in experimental trials some individuals have had these inserted.
“However, the general public should not run away with the idea that this is going to be routine surgery for blind people in the immediate future because there is an enormous amount to learn.”
April 22, 2008
Source: The Times