Bionic Eye Sees the Light of Day
While it may sound like something more likely to be read in science fiction than reality, the world’s first bionic eye received FDA approval last week.
Years in the making, the retinal prosthesis, labeled Argus II, is able to restore partial eyesight to people blinded with Retinitis pigmentosa, a degenerative eye disease than inflicts around 100,000 Americans.
People with the degenerative eye disease have found very little solace in the past, as the disease destroys photoreceptors in the eye – a tissue layer at the back of the eye – that process light. The symptoms vary, but those afflicted with RP experience ailments such as night blindness to trouble adjusting from light environments to dark, to lack of central vision (and other a lack of peripheral) to some finally going blind. However, with Second Sight Medical Products’s retinal prosthesis, the device implanted on the retina can stimulate the cells as if receiving light, triggering them to transmit an image to the brain.
“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 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.”
While the number of electrodes limits patients and the device is unable to restore sight completely, already some of the patients who took part of the clinical trials have been able to make out the shape of a curb while walking as others were able to read the headlines of a newspaper.
“This is a game changer in sight-affecting diseases,” Second Sight Chief Executive Robert Greenberg told the Wall Street Journal,” that represents a huge steps forward for the field and for these patients who were without any available treatment options until now.”
While patients are able to see in black and white, Second Sight’s hope is for color vision. Some of the challenges ahead for the team is how to add more electrodes into the tiny chip that sits on the retina – about 5 millimeters by 7 millimeters – to stimulate enough cells in the retina to produce a good quality image. “The fact that many patients can use the Argus implant in their activities of daily living … has been beyond our wildest dreams,” stated Mark Humayun, a University of Southern California medical professor and doctor who was involved with the Argus, added, “yet the promise to the patients is real and we expect it only to improve over time.”
The Argus II will be available to patients later this year in U.S. clinical center. (The device has already been approved in Europe.) Brian Mech, vice president of business development at Second Sight, reported to Reuters that while the system will cost more than $100,000, the company “is working with insurance companies and Medicare to win coverage and ease out of pocket expenses for patients.” The device is available only to patients who have had vision in the past and currently limited to adults 25 or older.
The device is a shining example of engineering integrity, as Mech said that the device was the result of “14 years, $200 million, and a lot of ‘intestinal fortitude.’”