People with geographic atrophy, an advanced form of age-related macular degeneration, face a future of incurable vision loss. Drugs approved in recent years can slow the disease's spread across the retina, but none can restore sight that is already gone.
Researchers are working on a retinal implant called PRIMA that could be the first treatment to restore lost sight, a potential game changer for patients. New data presented on Sunday at the 130th annual meeting of the American Academy of Ophthalmology suggest that the vision it restores is lasting.
Over 5 million people globally are affected by advanced macular degeneration, and it is the most common cause of irreversible blindness among the elderly.
"Conventional therapies attempt to slow disease progression," said Dr. Joseph Martel, an ophthalmologist in Rancho Cordova, Calif., and the study's lead author. "PRIMA directly restores lost functional vision in patients with geographic atrophy. I look forward to seeing these results replicated in the real world in Europe, and I hope these data can also support approval in the US so I can offer PRIMA to my patients."
The system has two parts. Surgeons place a wireless chip, about two millimeters across and thinner than a human hair, beneath the retina, where light-sensing cells have died. The patient then wears a pair of glasses with a built-in camera. The glasses capture the scene in front of the wearer and project it onto the chip as infrared light. The chip converts that light into electrical signals, which pass through the retina's surviving cells to the brain.
The trial, called PRIMAvera, enrolled 38 patients at 17 centers across Europe. After surgery, the patients went through vision rehabilitation to learn to use the device. Results from the first year, published in The New England Journal of Medicine in 2025, showed meaningful improvement. The new findings cover what happened over the following two years.
When the study began, the patients' vision averaged roughly 20/460. That is worse than the 20/400 needed to read the large "E" at the top of a standard eye chart. Among the 18 patients evaluated at three years, vision with the device averaged about 20/120. That is an improvement of nearly six lines on an eye chart, slightly more than the five-line gain seen at one year.
Seventy-eight percent of those patients, 14 of 18, improved by at least two lines, which researchers consider clinically meaningful. The same share improved by at least three lines.
The implant did not appear to harm the vision patients still had. With the device switched off, sight in the implanted eye stayed essentially unchanged over three years. Meanwhile, vision in the patients' untreated eyes continued to decline, as the disease typically does.
Most serious complications in the trial came in the first year and were linked to the implant surgery. Between the 13th and 36th months, three patients each had one serious eye-related adverse event.
The findings come with caveats. The trial had no control group, and at 36 months, 27 of the original 38 patients were evaluable for safety and 18 for efficacy. The summary did not say why the others were not assessed. If patients who did poorly were more likely to leave the study, the remaining group could make the device look more effective than it is.
PRIMA received the CE mark in July, which allows it to be sold in Europe. It has not been approved in the United States. PRIMA is based on work originally done at Stanford University and is being developed by Science Corporation of California.
Reference:
American Academy of Ophthalmology. “Retina.” Accessed October 12, 2026.
https://www.aao.org/eye-health/anatomy/retina-103
(Newswise/ARC)
