Vision Restored for Some with Retinal Implant, Offering Hope for AMD Patients

A groundbreaking new device is offering a glimmer of hope for individuals suffering from advanced age-related macular degeneration (AMD), a leading cause of irreversible blindness affecting over 5 million people worldwide. Results published in the New England Journal of Medicine in October 2025 detail the success of the PRIMA (photovoltaic retina implant microarray) system in restoring functional central vision.

Understanding Age-Related Macular Degeneration

AMD progressively damages the central field of vision due to damage to the light-sensing cells, known as photoreceptors, in the retina. As the condition advances, this damage leads to blurred central vision, making everyday tasks like reading and recognizing faces difficult. Currently, there are no therapies to fully restore vision lost to geographic atrophy, a form of advanced AMD.

How the PRIMA System Works

The PRIMA system aims to bypass damaged photoreceptors by directly stimulating surviving retinal cells. The system consists of two key components: a 2×2 millimeter subretinal implant, just 30 micrometers thick, and a pair of specially designed glasses. The glasses contain a camera that captures images and projects near-infrared light onto the implant. This light is then converted into electrical pulses, stimulating the retinal cells and transmitting visual information to the brain.

Unlike previous retinal prostheses, PRIMA is photovoltaic, meaning it requires only light to generate an electric current, eliminating the need for external power sources or cables extending from the eye. The implant was originally developed by Professor Daniel Palanker at Stanford University.

Clinical Trial Results

An international, multi-center clinical trial involving 38 participants with geographic atrophy assessed the efficacy of the PRIMA system. The study, conducted at 17 medical centers across five European countries, showed promising results.

• 81% of participants (26 out of 32 who completed 12 months of follow-up) experienced a clinically meaningful improvement in visual acuity, defined as an improvement of at least 0.2 logMAR (logarithm of the minimum angle of resolution).
• The average improvement in visual acuity was 25.5 letters on an ETDRS letter chart (more than 5 lines).
• 84% of participants reported the ability to read letters, numbers, and words, indicating a restoration of functional central vision.

Participants were able to adjust the zoom and contrast settings on the glasses to optimize their vision.

Safety and Side Effects

A total of 26 serious adverse events occurred in 19 participants, with 81% of these events occurring within two months of surgery. However, 95% of these events resolved within two months of onset. Common side effects included ocular hypertension (high pressure in the eye), tears in the peripheral retina, and subretinal hemorrhage (blood collecting under the retina).

Future Developments

While the PRIMA system has shown promising results, it is still in its early stages of development. Science Corporation acquired the device from Pixium Vision in 2024. Current limitations include the device’s ability to only provide black and white images and its relatively low resolution (378 pixels). Researchers are working on improving the resolution and adding grayscale and color capabilities. A new version of the implant, currently being tested on rats, is significantly smaller (20 microns wide) and has a higher pixel count (10,000 pixels).

Dr. Frank Holz, a lead investigator in the study, expressed optimism about the future of the PRIMA system, stating that this is just “the beginning of a journey.”