After being treated with an combined electronic eye implant with augmented reality glasses, people with vision loss have regained reading vision. 84% of the participants were able to read letters, numbers, and words using prosthetic vision through an eye that had previously lost vision due to an untreatable progressive eye disease, geographic atrophy with dry age-related macular degeneration (AMD).
The wireless retina implant has shown its utility in advanced AMD, according to the results of a clinical trial published in The New England Journal of Medicine (NEJM). This disease is the leading cause of irreversible blindness in older adults and affects more than five million people worldwide.
This international, multicenter trial was jointly led by José-Alain Sahel, director of the Vision Institute at the University of Pittsburgh Medical Center, Pennsylvania; Daniel Palanker, professor of Ophthalmology at Stanford University, both in the United States, and Frank Holz, MD, professor of Ophthalmology at the University of Bonn, Germany.
Sheila Irvine, one of the Moorfields patients who participated in the clinical trial and was diagnosed with age-related macular degeneration, commented: "I wanted to participate in research to help future generations, and my eye doctor suggested contacting Moorfields. Before the implant, it was like having two black discs in my eyes, with the outer part distorted."
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Of the 32 participants who completed 12 months of follow-up, 26 (81%) achieved clinically significant improvements in their visual acuity, and 27 participants (84%) reported using vision prostheses at home to read numbers or words. On average, participants improved by 25 letters (approximately five lines) on a standard eye chart when using the device. 81% of the participants improved by 10 letters or more.
Sahel, the study's lead author and director of the Department of Ophthalmology at the University of Pittsburgh School of Medicine, points out that "it is the first time" that an attempt to restore vision has achieved such results in a large number of patients. According to his data, "over 80% of patients were able to read letters and words, and some could even read pages of a book. This is something we couldn't even imagine when we started this project, along with Daniel Palanker's group, 15 years ago."
"She was an avid reader and wanted to get that back," says Sheila Irvine. "I was nervous, excited, all of that. I didn't feel any pain during the operation, but still, you were aware of what was happening. It's a new way of seeing through the eyes, and it was very exciting when I started to see a letter. It's not easy to learn to read again, but the more hours I dedicate, the more I learn."
As AMD progresses, central vision becomes increasingly blurry due to the irreversible damage of photosensitive cells in the central part of the retina. In a healthy retina, these cells capture ambient light and transform it into electrical pulses, which are then sent to the nerve cells lining the back of the eye and ultimately to the brain through the optic nerve.
Stimulation of retinal cells
The PRIMA system, originally designed by Palanker, replaces these lost photoreceptors with a 2x2 mm wireless implant that converts light into electrical signals to stimulate the remaining retinal cells. A camera mounted on specialized glasses captures images and projects them onto the implant using invisible near-infrared light. The implant converts light into electrical pulses, restoring the flow of visual information to the brain. Patients can adjust zoom and contrast to enhance functional vision.
The PRIMAvera trial enrolled 38 participants aged 60 or older at 17 centers in five European countries: France, Germany, Italy, the Netherlands, and the United Kingdom. After a year using the system, all procedure-related adverse effects had resolved, and most participants showed significant improvement in their ability to read letters on the eye chart. One participant improved by up to 59 letters (or 12 lines).
"Although we still cannot fully restore 20/20 vision with the implant alone, in Pittsburgh, we are investigating methods that could further improve people's quality of life and take them above the threshold of legal blindness," said Sahel.
Based on the results of the new study, the device manufacturer, Science Corporation, a technology company closely linked to neuroscience, has applied for clinical use authorization in Europe and the United States. The University of Pittsburgh was the first U.S. center to implant the PRIMA device in 2020, in a study led by associate professor of Ophthalmology, Joseph Martel.