Bionic eye seeks to follow success of cochlear implants

Sunday, May 26, 2002

NEW YORK -- When 68-year-old Robert Rosene became a bionic-eyed man, he didn't get the Six Million Dollar Man's telescoping vision.

Rosene, of St. Charles, Ill., was all but pitch-black blind before getting a microchip slipped into his retina last year. He now sees globs of light and shadow, but not his wife's face.

For Cora Jean Kleppe, 73, who got a bionic ear last month, silence has been upended by a cascade of sounds: the ding of the microwave oven, the eager chatter of her grandkids and the tweeting of birds in her San Mateo, Calif. garden.

So far, just six patients have received experimental eye implants.

All have shown slight vision improvements. If bionics can do to eyes what it has to ears -- dramatically upgrading hearing in some 70,000 recipients -- mechanical implants could take some of the ache out of growing old.

"It's such a blessing to think that I'm living in this day and age," Kleppe said. "To hear these sounds again, it's so wonderful."

Bionics, the ages-old practice of replacing body parts with mechanical devices, has quietly grown more sophisticated over the past few decades, with successful integrations of artificial hands, knees and organs.

The type of hearing device that Kleppe received last month, a cochlear implant made by Advanced Bionics Corp., is now so successful that it is replacing the hearing aid in patients who are hard of hearing, rather than deaf, said Dr. Anil Lalwani, director of the Douglas Grant Cochlear Implant Center at the University of California at San Francisco.

The implant is a two-piece device, with a small receptor surgically mounted in the skull that trails a wire into the cochlea, the coiled part of the inner ear that converts sound vibrations into nerve impulses sent to the brain.

A separate speech processing component mounts behind the ear, using a magnet to hold it close to the implant. The processor's microphone picks up sound, converts it to a digital signal and passes it to the implant.

Installing a bionic ear like Kleppe's is a $50,000-$60,000 procedure, usually at least partially covered by insurance.

Accommodates crudeness

The rousing success of the cochlear implant is raising hopes that experiments in bionic vision, like the silicon-chip artificial retina used by Rosene, will soon bolster failing sight organs.

The implants count one huge advantage in their favor. The human brain's powerful processing abilities accommodate the crudeness and imperfections of the mechanical eyes and ears, allowing them to serve as a relatively unsophisticated patch on an otherwise sound hearing or sight system.

The brain "needs really a small amount of information to reconstruct speech," said Dr. William Heetderks, program director for neural prosthesis at the National Institute of Health in Bethesda, Md. "It's reasonable to believe that the same thing is possible in the visual realm."

A handful of researchers are plumbing the potential of the bionic eye, including Wheaton, Ill.-based Optobionics Corp., led by Dr. Alan Chow, a pediatric ophthalmologist whose artificial silicon retinas have slightly improved the vision of the six patients who've received them.

The surgery process involves cutting a tiny pocket in the retina and inserting a microchip that packs 5,000 microscopic solar cells onto a pinhead-sized disc thinner than a human hair. The chips convert light into electricity, which stimulates retinas degraded by retinitis pigmentosa and macular degeneration, two common causes of untreatable blindness.

Chow, who devised the implants with his brother Vincent, an electrical engineer, said he and other doctors involved in the project noticed vision improvements during initial examinations of the six.

Testing on humans

After successes in tests on animals, Optobionics got U.S. Food and Drug Administration approval to try the chips on humans last January. The results of those tests have yet to be formally calculated or released, but Chow and his patients have spoken informally about improvements in their vision.

Three patients, including Rosene, got the implants in June 2000. Three more received them last July. Optobionics is seeking four more patients this summer, said Dave McComb, the 12-person company's spokesman.

Results vary from those of Rosene, who went from seeing nothing in his right eye, to being able to see his porch light, to a patient who went from being able to count fingers held a few feet from is face, to seeing a migrating flock of geese in the sky overhead.

"He can use eating utensils now," Chow said of the patient who saw geese. "Many blind people use their fingers to feel the food."

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