Primary Endpoint at 12 Months
81%
of participants achieved clinically meaningful visual acuity improvement (≥10 ETDRS letters) n=32, 95% CI, 64-93, P<0.0011
Information for Healthcare Professionals
4 in 5 patients in the PRIMA clinical study demonstrated clinically meaningful improvement of visual acuity at 12 months.1
PRIMA is an investigational retinal implant designed to restore central vision in geographic atrophy due to dry AMD.
Addressing an Unmet Need in Geographic Atrophy
Geographic atrophy is an advanced form of "dry" AMD, characterized by the progressive and irreversible loss of photoreceptors and retinal pigment epithelial cells, culminating in profound central vision impairment.
Current therapeutic options (complement inhibitors and cell therapies) are only partially effective in slowing disease progression and are unable to stop the natural course of the disease. Conventional low-vision aids rely on magnification and do not address the underlying sensory deficit.1
Mechanism of Action
PRIMA is designed to bypass damaged photoreceptors to generate a new central visual percept while preserving natural peripheral vision.
Capture
A built-in camera on the glasses captures the visual scene. A pocket processor manages real-time signal processing and wireless transmission of stimulation parameters.
Project
An integrated projector transmits patterned near-infrared light through the pupil onto a photovoltaic array (2 × 2mm; 30µm thick) positioned subretinally.
Stimulate
378 photovoltaic pixels generate localized electrical pulses that stimulate adjacent bipolar cells of the inner nuclear layer. These signals propagate through the ganglion cell layer, traverse the optic nerve, and are interpreted in the visual cortex.
Eligibility
The following criteria were used to evaluate patient suitability in the PRIMA clinical study:
| Criterion | Specification |
|---|---|
| Age | 60 years or older |
| Diagnosis | Bilateral GA due to AMD |
| Visual acuity | BCVA ≥ 1.2 logMAR (≤ 20/320 Snellen; ≤ 0.06 decimal) |
| Lesion size | Foveal atrophy > 4.5mm2, > 2.4mm minimum diameter |
| Rehabilitation capacity | Motivated and able to attend scheduled follow-up visits and complete the vision rehabilitation program |
Clinical Evidence
The PRIMA clinical trial was a prospective, multicenter, single-group (single-arm) study, evaluating the safety and efficacy of the PRIMA System in 38 patients with GA involving the central macula due to AMD.
The results were published in the The New England Journal of Medicine in October 2025.1 In a follow-up NEJM editorial, author Jacque Duncan, M.D., described PRIMA as “the first treatment to restore vision” in patients with advanced GA.2
Highlights of the PRIMA Clinical Study
Mean Gain in Visual Acuity
~25 letters
at 12 months; best individual improvement: 59 letters1
Reading at Home
84%
reported reading letters, numbers, and words with artificial vision1
Data collected over a period of 12 months showed that the PRIMA Implant can be safely implanted under the atrophic macula and restore central vision while preserving natural peripheral vision.1
Safety Profile
The safety profile of the PRIMA System was evaluated across all 38 participants in the PRIMA clinical study through 12 months of follow-up. The overall profile was consistent with that expected for subretinal vitreoretinal surgery, and the benefit-risk balance was considered favourable by the independent Data Safety Monitoring Board.1
Colour fundus and OCT images of the PRIMA Implant, before and 12 months after implantation.
Implantation Procedure
In the PRIMA clinical study, the implant was delivered subretinally via pars plana vitrectomy. Surgery was an average duration of 2.0 to 2.5 hours, performed by a trained vitreoretinal surgeon.
This video shows how the PRIMA Implant is placed beneath the retina, and its mechanism of action.
Vision Rehabilitation
In the PRIMA clinical study, patients followed a structured rehabilitation program of 60 hours of training with a dedicated vision rehabilitation specialist. Patients who completed the full program were more likely to achieve the best possible outcome.
The referring retinal specialist remained part of the care team, resuming ongoing follow-up after rehabilitation.
Expert Opinions
“Compared to previous bionic vision strategies and implants, it is a photovoltaic system that does not require any cables or wiring going in and outside the eye.”
Professor & Chairman, Dept. of Ophthalmology, University of Bonn
“It's the first time an artificial retinal implant has worked so well in a large study, with a procedure that could be carried out by multiple surgeons.”
Chair, Dept. of Ophthalmology, University of Pittsburgh; Founder, Institut de la Vision, Paris
“PRIMA needed to have a procedure that was something you could easily do in your standard practice.”
Vitreoretinal Surgeon, Moorfields Eye Hospital; Associate Professor, Institute of Ophthalmology, University College London
References
- Holz FG, Le Mer Y, Muqit MMK, et al. Subretinal photovoltaic implant to restore vision in geographic atrophy due to AMD. N Engl J Med. 2026;394(3):232-242. doi:10.1056/NEJMoa2501396. *Efficacy results include use of digital zoom and contrast.
- Duncan J. Restoring vision for patients with AMD and geographic atrophy. N Engl J Med. 2026;394(3):298-301. doi:10.1056/NEJMe2514592.
CAUTION: Investigational device. Not commercially available outside the EU/EEA.