Blind Patient Successfully Reads Words Stimulated Onto the Retina
The findings of this study potentially have major implications for products helping blind patients with their condition.
-- by Michael Harkin
The Argus II is a neuroprosthetic device that has allowed several blind patients to be able to see movement, objects, and color. Developed by researchers at the company Second Sight, it uses a small camera on a pair of glasses, along with a portable processor and a microchip that transfers information to the retina via implanted electrodes. The device is intended primarily to treat people who suffer from retinitis pigmentosa (RP).
It is currently undergoing clinical trials, but several research projects are ongoing for potential improvements of the device. A new study published today in Frontiers in Neuroprosthetics discusses the findings of one such Argus II research project led by Dr. Thomas Lauritzen, Ph.D.
In this new study, Lauritzen and his team of researchers were able to stream patterns of braille directly on to a blind male patient’s retina, allowing him to read four-letter words quickly and successfully. This breakthrough could have major implications for future products and treatments aiding those who deal with blindness every day.
The Expert Take
“We have earlier shown that subjects can read regular text, which is a great achievement in itself,” said Lauritzen in an interview with Healthline. “With this sensory substitution method of visual braille, we have shown we can speed reading up by almost 20 times in a subject from tens of seconds to approximately 1 second per letter. This can have huge practical applications.”
The possibility of increased reading speed might mean that this system of direct streaming will be integrated into a later version of Second Sight’s product. “If it is implemented as an option in future versions of our software,” said Lauritzen, “it will be an addition to the current system and options.”
Source and Method
This particular test did not use the camera, which is the usual form of input for the blind patients who have tested the Argus II. “In this clinical test with a single blind patient, we bypassed the camera that is the usual input for the implant and directly stimulated the retina,” said Dr. Thomas Lauritzen, Ph.D., the lead author of the study, in a press release. “Instead of feeling the braille on the tips of his fingers, the patient could see the patterns we projected and then read individual letters in less than a second with up to 89 percent accuracy.”
The Argus II implant has 60 electrodes in a grid pattern, attached to the retina. Using computer signals, braille letters were projected by the researchers onto six different points on this grid. Letters, as well as two- to four-letter words, were shown for half a second in a series of tests. The patient was able to tell the difference between different signals appearing on different electrodes, and had an 80 percent success rate reading the short words that were projected.
The key finding of the study is the importance of continued testing of neuroprosthetic devices that could help blind people with their condition. Additionally, the findings of the study might be integrated into these kinds of products in the future.
The Argus II, once approved, would primarily be for treating RP patients. Second Sight intends to do studies into the possibility of using this device to help patients with macular degeneration, an eye condition that very commonly affects older people.