October 4, 2009

Burst of Technology Helps Blind to See

Barbara Campbell is part of a worldwide experiment testing whether electrodes implanted in the eye can restore sight.

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, Ms. Campbell, now 56, would have been thrilled to see something. Anything.

Now, as part of a striking experiment, she can. So far, she can detect burners on her stove when making a grilled cheese, her mirror frame, and whether her computer monitor is on.

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.

The project, involving patients in the United States, 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.

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, Calif., 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 program director at the National Eye Institute. “They’re able to get some sort of vision.”

Scientists involved in the project, the artificial retina, say they have plans to develop the technology to allow people to read, write and recognize faces.

Advances in technology, genetics, brain science and biology are making a goal that long seemed out of reach — restoring sight — more feasible.

“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.”

More than 3.3 million Americans 40 and over, or about one in 28, are blind or have vision so poor that even with glasses, medicine or surgery, everyday tasks are difficult, according to the National Eye Institute, a federal agency. That number is expected to double in the next 30 years. Worldwide, about 160 million people are similarly affected.

“With an aging population, it’s obviously going to be an increasing problem,” said Michael D. Oberdorfer, who runs the visual neuroscience program for the National Eye Institute, 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, Miss., 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 this country. The surgeon, Dr. 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.

Ms. Campbell’s artificial retina works similarly, except it produces the sensation of sight, not tingling on the tongue. Developed by Dr. 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.

It is so far being used in people with retinitis pigmentosa, in which photoreceptor cells, which take in light, deteriorate.

Gerald J. Chader, chief scientific officer at the University of Southern California’s Doheny Retinal Institute, where Dr. Humayun works, said it should also work for severe cases of age-related macular degeneration, the major cause of vision loss in older people.

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