"Bionic" eye restores vision after three decades of darkness
SOURCE
When vision fails, it's often the result of damage to the eye caused by an injury or degenerative disease. In an attempt to restore such vision loss, researchers for more than a decade have been working to develop an optical prosthetic that can restore sight by delivering images directly to the brain. And it appears they succeeded. The
BBC reports that a 73-year-old man identified only as Ron, who received an optical implant at
Moorefields Eye Center in London last summer, can see again for the first time in 30 years.
The BBC hails the Argus II prosthetic—made by Second Sight Medical Products, Inc., in Sylmar, Calif.—as a "bionic eye," although it's actually a wireless communication system implanted in the damaged eye that captures images and relays them to the brain.
The system works with the aid of eyeglasses, which hold a camera mounted on one of the lenses that captures images and sends the information to a video processor, also located on the glasses, according to the description of the technology on
Second Sight's Web site. After the video processor converts the images to an electronic signal, a transmitter on the glasses sends that information wirelessly to a receiver attached to the surface of the eye. From there, the information is sent through a tiny cable to an electrode array implanted in the retina, stimulating it to emit electrical pulses. These pulses trigger signals in the retina that travel through the optic nerve to the brain, which perceives patterns of light and dark spots that correspond to the electrodes stimulated.
In addition to Ron, 17 other patients in the U.S., Europe and Mexico are trying out the Argus II system to see if it's safe and effective in restoring at least partial vision to people suffering from Retinitis Pigmentosa (RP), a genetic eye disease that causes blindness. Preliminary results indicate that there were no device failures and few "serious adverse events," the most serious of which resulted in the removal of an implant without difficulty or harm to the individual, the
company reported in November. Eleven of the study participants reported that they could locate a door up to 20 feet (six meters) away and see and walk to the end of a 20 -foot line drawn on the floor with the aid of the implant.
"The retinal implant technology is advancing at an impressive rate, but the most interesting thing will be to see how the volunteer subjects who have received the initial Argus II implants will fare as time goes on," Pezaris says. "The brain is highly adaptable and, while some of the initial reports in the scientific literature suggest that retinal implants may have serious problems with poor resolution, it may be that with time, the visual system of implanted patients will adapt to the new signals, the new form of sight, with slowly improving functionality." This has been the case with
cochlear implants, he adds, where the brain needs some months to adapt to the new sensory patterns.
VisionCare Ophthalmic Technologies, Inc., in Saratoga, Calif., is testing visual prosthetic devices designed for individuals with age-related macular degeneration, a disorder of the central retina, or macula, that causes the afflicted person to see a dark spot in the center of his or her field of vision, impairing the ability to read, recognize faces and watch TV. (
Scientific American.com first wrote about this technology in August 2007.) VisionCare's Miniature Telescope prostheses are mini telescope-like devices that work with the eye's
cornea (the transparent, dome-shaped window covering the front of the eye) like a telephoto system, rendering an enlarged retinal image that reduces the area of diminished vision.
Once implanted, the device protrudes only 0.1 to 0.5 millimeter beyond the surface of the pupil but does not touch the corneal endothelium, a layer of cells lining the back of the cornea. The Miniature Telescope has received CE Mark [[
http://www.cemarking.net/ ]] approval (a mandatory European certification indicating conformity with certain health and safety requirements) and is currently being reviewed by the U.S. Food and Drug Administration, the company
reports on its Web site.
Ben - While this story is more than a year old, it's relevant again because of this story published July 9, 2010:
FDA Approves Telescopic Bionic Eye Implant
SOURCE
The FDA Tuesday announced that it had approved a telescopic eye implant that can help the visually impaired. The procedure involves removing the lens of the eye completely and replacing it with the now FDA-approved implant, which is capable of magnifying things by 2.2-2.7 times.
The implant is aimed at elderly people (over the age of 75) with macular degeneration, a condition that results in a loss of vision in the center of the visual field because of retinal damage. Created by
VisionCare Ophthalmic Technologies, the telescope projects images in your field of view onto healthy areas of your central retina outside of the degenerated macula. The image is enlarged, which reduces the effect the blind spot has on central vision.
While VisionCare promises that people with the implant will be able to move their eye naturally, they do warn that peripheral vision on that side will be affected. It's for this reason that a patient can't have the telescope implanted into both eyes. The FDA also said that patients will need to undergo rehab to get used to using their new bionic eye in tandem with their untreated eye. There's also the possibility that because of the size of the device, patients may need a corneal transplant.
Clinical trials involving
219 patients resulted in vision improvement (from severe or profound impairment to moderate impairment) for 75 percent of the participants.
Ben - Gibson Rickenbacker better get ready!
Seriously though, this is pretty damned cool.
Another step towards making a truly bionic human being!
