German researchers have invented a microchip that helps blind people see lines and colors.
The microchip — 3 x 3 mm in size and developed by the German biotechnology firm Retina Implant AG — is implanted below the surface of the retina where it electronically stimulates the optical tissues, reports New Horizons. The chip is designed to help those who have retinitis pigmentosa (RP), a degenerative eye disease that affects 200,000 people in the United States and Europe. It has had successful clinical trials in Germany and is now being tested in Hong Kong and Britain, and will then move to trials in the United States.
RP is a disease that mainly affects the photoreceptors in the retina by slowly causing them to degrade until the patient becomes blind. Although the disease is incurable, the nerves of the retina remain functional. The retinal implant chip takes advantage of that situation by stimulating those nerves.
The medical device is a light-sensitive, externally powered microchip. It is made up of 1,500 active microphotodiodes, each with its own amplifier and electrode for stimulating the retinal nerves. Also, there are 16 electrodes to stimulate the nerves directly and to test the interface between electrodes and neurons. Light falling on the microphotodiode array stimulates the nerves, generating patterns on the retina with a resolution of 38 x 40 pixels.
The result is some degree of artificial vision, which is not like normal sight. New Horizons explains further:
It’s more in the form of lines and colors that the patient learns to interpret. The researchers say results in clinical trails have been better than expected. Provided contrast is strong enough, patients can identify objects, such as geometric shapes and fruit, observe people moving about the room, read numbers on dice and even read large letters and make out words on a screen.
In a clinical study, 26 patients who had been blind for more than a decade received the implant, and the results have been published in the Proceedings of the Royal Society B: Biological Sciences (Proceedings B). As for U.S. trials, once the U.S. Food and Drug Administration approves the device, trials will be held at the Wills Eye Institute in Philadelphia.
To improve the implant, more receptors will be needed, which will increase resolution. Researchers also plan to find out which other degenerative eye conditions may be helped by the device.
Dale McGeehon has been a journalist and editor for more than 25 years, covering chemical regulation and testing for Pesticides and Toxic Chemical News and innovations in material sciences for the National Technology Transfer Center. His writing credits include Omni and College Park magazines and The New York Times.