BackA burst of technology returns vision to the blind
A burst of technology returns vision to the blind
PremiumRegaining sight: Barbara Campbell in New York. She relies on electrodes implanted in her eyes for vision. Beatrice De Gea / NYT
Blindness first began creeping up on Barbara Campbell when she was a teenager, and by her late 30s, her eye disease had stolen what was left of her sight.
Reliant on a talking computer for reading and a cane for navigating New York City, where she lives and works, Campbell, now 56, would have been thrilled to see something. Anything.
She is beginning an intensive three-year research project involving electrodes surgically implanted in her eye, a camera on the bridge of her nose and a video processor strapped to her waist.
Some of the 37 other participants further along in the project can differentiate plates from cups, tell grass from sidewalk, sort white socks from dark, distinguish doors and windows, identify large letters of the alphabet, and see where people are, albeit not details about them.
Linda Morfoot, 65, of Long Beach, California, blind for 12 years, says she can now toss a ball into a basketball hoop, follow her nine grandchildren as they run around her living room and “see where the preacher is" in church.
“For someone who’s been totally blind, this is really remarkable," said Andrew P. Mariani, a programme director at the National Eye Institute (NEI), a US agency. “They’re able to get some sort of vision."
Scientists involved in the project, an artificial retina, say they have plans to develop the technology to allow people to read, write and recognize faces. The project, involving patients in the US, Mexico and Europe, is part of a burst of recent research aimed at one of science’s most sought-after holy grails: making the blind see.
That goal long seemed out of reach because the visual system of the eye and the brain is so complex. But advances in technology, genetics, brain science and biology are making several approaches, both new and long-studied, more viable. Some, including the artificial retina, are already producing results.
“For a long time, scientists and clinicians were very conservative, but you have to at some point get out of the laboratory and focus on getting clinical trials in actual humans," said Timothy J. Schoen, director of science and preclinical development for the Foundation Fighting Blindness. Now “there’s a real push", he said, because “we’ve got a lot of blind people walking around, and we’ve got to try to help them".
At least 3.3 million Americans 40 and over, or around one in 28, are blind or have vision so poor that even with glasses, medicine or surgery, everyday tasks are difficult, according to NEI. That number is expected to double in the next 30 years. Worldwide, around 160 million people are similarly affected.
“With an ageing population, it’s obviously going to be an increasing problem," said Michael D. Oberdorfer, who runs the visual neuroscience programme for NEI, which finances several sight-restoration projects, including the artificial retina. Wide-ranging research is important, he said, because different methods could help different causes of blindness.
The approaches include gene therapy, which has produced improved vision in people who are blind from one rare congenital disease. Stem cell research is considered promising, although far from producing results, and other studies involve a light-responding protein and retinal transplants.
Others are implanting electrodes in monkeys’ brains to see if directly stimulating visual areas might allow even people with no eye function to see.
And recently, Sharron Kay Thornton, 60, from Smithdale, Mississippi, blinded by a skin condition, regained sight in one eye after doctors at the University of Miami Miller School of Medicine extracted a tooth (her eyetooth, actually), shaved it down and used it as a base for a plastic lens replacing her cornea.
It was the first time the procedure, modified osteo-odonto-keratoprosthesis, was performed in the US. The surgeon, Victor L. Perez, said it could help people with severely scarred corneas from chemical or combat injuries.
Other techniques focus on delaying blindness, including one involving a capsule implanted in the eye to release proteins that slow the decay of light-responding cells. And with BrainPort, a camera worn by a blind person captures images and transmits signals to electrodes slipped onto the tongue, causing tingling sensations that a person can learn to decipher as the location and movement of objects.
Campbell’s artificial retina works similarly, except it produces the sensation of sight, not tingling on the tongue. Developed by Mark S. Humayun, a retinal surgeon at the University of Southern California, it drew on cochlear implants for the deaf and is partly financed by a cochlear implant maker.
Campbell, a vocational rehabilitation counsellor for New York’s Commission for the Blind and Visually Handicapped, has long been cheerfully self-sufficient, travelling widely from her fourth-floor walk-up, going to the theatre, babysitting for her niece in North Carolina.
But little things rankle, like not knowing if clothes are stained and needing help shopping for greeting cards. Everything is a “grey haze—like being in a cloud", she said.
The device will not make her “see like I used to see", she said. “But it’s going to be more than what I have. It’s not just for me—it’s for so many other people that will follow me."
©2009/The NEW YORK TIMES
Unlock a world of Benefits! From insightful newsletters to real-time stock tracking, breaking news and a personalized newsfeed – it's all here, just a click away! Login Now!
