A landmark international clinical trial has demonstrated the potential of a subretinal photovoltaic implant to restore central vision in patients with geographic atrophy (GA), the advanced form of dry age-related macular degeneration (AMD).
Published in the New England Journal of Medicine on 20 October, the study evaluated the PRIMA system – a wireless retinal implant paired with augmented-reality glasses – across 38 patients (of whom 32 were assessed at 12 months) in five European countries.
The trial found that 81% of participants who completed 12 months of follow-up achieved a clinically meaningful improvement in visual acuity, defined as a gain of ≥0.2 logMAR.
The PRIMA system works by replacing lost photoreceptors with a 2×2 mm implant that converts near-infrared light into electrical signals. These signals stimulate surviving retinal cells, allowing visual information to reach the brain. A camera embedded in the glasses captures images and projects them onto the implant, enabling patients to perceive vision through previously blind eyes.
A BBC report claimed participants improved by an average of 25 letters – equivalent to five lines – on a standard eye chart. Sheila Irvine, a participant in the trial from the UK, told the BBC she regained the ability to read prescriptions, do crosswords, and even navigate public transport using the device.
Dr Mahiul Muqit , consultant ophthalmic surgeon at Moorfields Eye Hospital in London, who led the UK arm of the trial, told the BBC it was “pioneering and life-changing technology”.
“This is the first implant that’s been demonstrated to give patients meaningful vision that they can use in their daily life, such as reading, writing.
“I think this is a major advance,” he said.
The trial, known as PRIMAvera (NCT04676854), was co-led by a consortium of ophthalmologists including Dr Frank Holz (University of Bonn), Dr Yannick Le Mer (Paris), and Dr Mahiul Muqit (Moorfields Eye Hospital, London).
Importantly, no participant experienced a decline in peripheral vision, and most adverse events resolved within two months post-surgery. The implant procedure, which involves a vitrectomy and insertion of the chip beneath the retina, can be completed in under two hours by trained vitreoretinal surgeons.
Science Corporation, the device manufacturer, has applied for clinical use authorisation in Europe and the United States. While full 20/20 vision restoration remains out of reach, researchers are optimistic that future enhancements could push patients above the legal blindness threshold.
