After more than two decades of research and development, the first retinal prosthesis has received European approval for clinical and commercial use. People blinded by degenerative eye disease will have the option of buying an implant that can restore their vision at least partially.
“It marks the beginning of an era in which sight will be restored at ever more astonishing levels,” says Robert Greenberg, president and CEO of Second Sight, the California company that developed the device.
Walter Wrobel, CEO of Retina Implant AG of Reutlingen, Germany, a startup that is carrying out trials of a similar device in several countries, says the approval is an exciting development for hundreds of thousands of people who suffer from diseases like retinitis pigmentosa.
Second Sight’s device, the Argus II, will cost around $115,000 and be available only through a small number of clinics in Switzerland, France, and the U.K. The company hopes to receive approval from the U.S. Food and Drug Administration by next year.
With the Argus II system, a camera mounted on a pair of glasses captures images, and corresponding signals are fed wirelessly to chip implanted near the retina. These signals are sent to an array of implanted electrodes that stimulate retinal cells, producing light in the patient’s field of view. The process works for people with retinitis pigmentosa because the disease damages only the light-sensing photoreceptors, leaving the remaining retinal cells healthy.
So far, the Argus II can restore only limited vision. “Patients can locate and recognize simple objects, see people in front of them, and follow their movement,” says Greenberg. “They can find doors and windows, follow lines, and in the best cases read large print slowly,” he says.
Getting this device to market is an important achievement, says Eberhart Zrenner, director of the Institute for Ophthalmic Research at the University of Tübingen in Germany and founder Retinal Implants AG. “On the other hand, the type of vision the Argus II can provide with 60 electrodes is quite limited,” he says.
Zrenner is developing a device for Retinal Implants that has more than 1,500 electrodes and captures images using light-sensitive photodiodes on the chip within the eye, instead of with an external camera. “It has the light-sensitive photodiodes positioned under the retina right at the place of the degenerated photoreceptors and therefore needs no camera outside,” he says.
Second Sight is also working on larger arrays. But for now, what distinguishes the Argus II from all other devices is its ability to survive long-term implantation in the human body. The Argus II has been tested in trials involving 30 patients. “We have done something that many people would have thought and did think was impossible,” says Greenberg.