"A game changer in sight-affecting diseases"
Those afflicted with Retinitis pigmentosa, a degenerative eye disease, undergo a very particular kind of medical trauma. They might experience night blindness, or nyctalopia. They might experience tunnel vision (the lack of peripheral vision) or, on the other hand, they might lack central vision. They might have latticework vision. They might have blurred vision. They might have trouble adjusting from light environments to dark, and vice versa. They might have trouble distinguishing among colors. They might, finally, go blind.
There hasn't been much that science has been able to do to help those who suffer from RP. While those afflicted with deafness might be able to turn to devices like cochlear implants to improve their hearing, those who suffer from retinal degeneration haven't been so lucky. Until now.
Enter the Argus II, a retinal prosthesis. Since RP affects only the retina, leaving the optic nerve intact, the bionic eye is able to substitute for the eye's natural photoreceptors by directly stimulating the retina's remaining cells -- which in turn pass the signal to the optic nerve. The device, developed by the firm Second Sight and already approved for use in Europe, just got approval from the Food and Drug Administration.
Here's how PopSci explains the bionic eye:
The Argus II works by substituting a small array of electrodes for the light-sensing cells that normally react to light by sending an electric signal toward the back of the retina. Those signals are relayed to the optic nerve behind the eye, and travel back along the nerve to the brain. In people with the genetic disease Retinitis pigmentosa, which affects about 100,000 people in the U.S. today, those light-sensing cells gradually stop working, resulting in total blindness.
In addition to the electrode array, which is implanted in the retina at the back of the eye, the Argus II system consists of a small video camera attached to a pair of eyeglasses and a visual processor the user carries around their waste. Data from the video camera is sent to the visual processor and then back to the glasses, where it is transmitted wirelessly to the embedded electrodes.
Argus II will be available to patients later this year in clinical centers in the U.S., and Second Sight says it will be adding locations to make the therapy more readily available to those who need it. And though the current technology allows the wearer to see only in black and white -- which is, of course, a vast improvement from the alternative -- the hope is that color vision will eventually be in Argus's future. Either way, though, the FDA approval is great news for those whose eyes could stand to be a little more bionic. As Second Sight CEO Robert Greenberg told the Wall Street Journal, "This is a game changer in sight-affecting diseases, that represents a huge step forward for the field and for these patients who were without any available treatment options until now."
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