Nov. 18, 2025
Back in Sight
A bookworm with macular degeneration reads again in promising study.
Designs on Aging-Ready
By Strategic Communications
Years ago, Sheila Irvine lost her central vision to age-related macular degeneration (AMD), a devastating disease that destroys light-sensing cells in the retina. AMD is the leading cause of irreversible blindness in older adults; more than 5 million people worldwide have an advanced form of the disease.
“I was an avid bookworm, and I wanted that back,” says the 70-year-old resident of Wiltshire, England.
Today, she’s reading and doing crossword puzzles again, as a participant in a large, multinational clinical trial of an experimental, wireless prosthetic-vision system called PRIMA. José-Alain Sahel, Distinguished Professor, Eye and Ear Foundation Professor, and Chair, Department of Ophthalmology at the University of Pittsburgh School of Medicine, as well as director of the UPMC Vision Institute, was senior author of a paper published in the New England Journal of Medicine (NEJM) about the trial.
“[This trial is] the first time that any attempt at vision restoration has achieved such results in a large number of patients. More than 80% of the patients were able to read letters and words, and some of them are reading pages in a book. This is really something we couldn’t have dreamt of when we started on this journey.”
José-Alain Sahel, Distinguished Professor, Eye and Ear Foundation Professor, and Chair, Department of Ophthalmology, as well as director of the UPMC Vision Institute
“[This trial is] the first time that any attempt at vision restoration has achieved such results in a large number of patients,” Sahel says. “More than 80% of the patients were able to read letters and words, and some of them are reading pages in a book. This is really something we couldn’t have dreamt of when we started on this journey.”
In 2020, UPMC became the first U.S. site to implant PRIMA, which was invented by Sahel’s longtime collaborator and cosenior author of the NEJM study, Daniel Palanker of Stanford University. The Pittsburgh-based feasibility study, which was led by Joseph Martel, associate professor of ophthalmology at Pitt School of Medicine, ran in parallel with the first-in-human trial in France. PRIMA is one of a number of vision restoration approaches being explored by the institute.
The PRIMA system compensates for lost retinal cells with a 2-by-2 mm wireless implant that converts light into electrical signals to stimulate remaining retinal cells. A camera mounted on specialized glasses captures images and projects them onto the implant using near-infrared light. The implant then converts the light into electrical pulses, restoring the flow of visual information to the brain. Patients can adjust zoom and contrast settings to enhance functional vision.
Of the 32 participants who completed the trial, 26 (81%) achieved clinically meaningful improvements in visual acuity. On average, participants improved by about five lines on a standard eye chart. One participant improved by 12 lines.
Based on these results, the device manufacturer, Science Corporation, has applied for clinical use authorization in Europe.
Although the implant alone can’t fully restore vision to 20/20, Sahel and his colleagues are now investigating additional approaches that could further improve quality of life and take patients above the threshold for legal blindness.