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Bionic Retinas Give Patients Sight
The Noof writes "
Yahoo News is running a
story about patients who have been given partial sight thanks to implants
of silicon-based bionic retinas.
" The article notes that the implant is having a "rescue effect" on the other components of the retina, restoring cells around the implant and making them useful again." Amazing stuff.
Wed May 8,10:30 AM ET
By Julie Steenhuysen
CHICAGO (Reuters) - They're not as fast as Lee Majors' Bionic Man, but six patients implanted with bionic retinas are seeing things they haven't seen in years.
Thanks to an artificial silicon retina, the six patients, many of whom were virtually blind, are rediscovering simple gifts of the sighted: the flight of a flock of geese, the pattern on a well-worn tablecloth, the face of a loved one.
The patients are part of a pilot study of a solar-powered microchip created by Optobionics, a private company based in Wheaton, Illinois.
The microchips, surgically implanted behind the retina, are smaller than the head of a pin and about half the thickness of a sheet of paper. They work by converting light into electrical impulses.
"What we are doing is trying to replace the function of photoreceptors," said Dr. Alan Chow, a pediatric ophthalmologist and chief operating officer of Optobionics. He developed the chip with his brother Vincent Chow, an electrical engineer.
Loss of light-sensing photoreceptor cells occurs in retinitis pigmentosa and macular degeneration, the two most common causes of untreatable blindness in developed countries, affecting at least 20 million people worldwide.
What Dr. Chow found is that the chips also seem to be stimulating remaining healthy cells.
"We're pretty excited. We initially expected only some light perception where the implant was. What seems to be improvement outside the areas was unexpected," he said.
'RESCUE EFFECT'
He said the device is having a "rescue effect" on the retina, restoring cells located near the implant site.
"What we think is happening is the implant is stimulating other cells around the retina. We're finding vision is improving not just where the implant is but also in areas near the implant," he said.
Chow is presenting his results later on Wednesday at the Association for Research in Vision and Ophthalmology annual meeting in Fort Lauderdale, Florida.
The trial includes three patients implanted with the chips for 9 months and three implanted for 21 months. Patients range in age from 45 to 76. All had lost their vision to retinitis pigmentosa, a hereditary condition in which the retina gradually degenerates.
Chow said the study was conducted to determine whether the device is safe. "In all six patients there are no signs of infection, inflammation, rejection or detachment," Chow said. He also said the chip has not eroded or moved, and none of the patients have experienced any pain or discomfort. "None can tell there is an implant in their eye," he said.
What they can tell is that they can see better.
Chow said one patient, who has had the implant for 9 months, saw his wife's face for the first time in years. The man, who previously could only see hand motions from four to five feet away, can now see cars from half a block away.
Another patient, who could not detect light even if a bright light was pointed at his eye, now knows when he needs to turn off his porch light.
For another patient, though, the implant has been a bit sobering, Chow said. The patient, who has begun to recognize faces, was disappointed to see how his own face had aged. But he was quick to note signs of age in his brother, who also received an implant.
Chow said his company will continue following the patients, with implants planned for the near future.
Optobionics' corporate investors include medical device giant Medtronic Inc. and CIBA Vision Corp., the eye care unit of Novartis AG.
I'm the Devil the Windows users warned you about.
You're pretty much right. There's an article in the June issue of Discover (which the website does not yet acknowledge the existence of, oh well) about corneal repairs, and one man in particular, blind since age 3, who had his corneas repaired. And yes, although his eyes now should allow him to see fine, he can't interpret what he sees. (One interesting side effect: he's immune to certain optical illusions, because he never learned to interpret images in the way that gives rise to the illusion!) Studies have been done with animals, too, in which animals are blindfolded at birth and their eyes only uncovered after they've reached adulthood - and although their eyes are physically fine, they're unable to actually use their vision. "Seeing" seems to be mostly post-processing by the brain.