We just got the news that a new ocular prosthesis has successfully restored partial vision to patients with irreversible blindness caused by geographic atrophy (the late stage of age-related macular degeneration that affects around five million people worldwide).
After two decades of research, a team of European and American scientists has completed a clinical trial involving 38 patients across 17 hospitals in five countries. The results, published Monday in the New England Journal of Medicine, show that most participants regained the ability to read letters, numbers, and words through the once-blind eye.
<social>https://x.com/NEJM/status/1980243868634533920</social>
Results after one year
The 32 participants, all over 60, suffered from geographic atrophy due to AMD, a progressive disease that destroys central vision.
One year after receiving the implant (called Prima) 27 patients (84%) recovered the ability to read, while 26 showed a "clinically significant" improvement in visual acuity, being able to read at least two additional lines on a standard eye chart. On average, visual acuity improved by five lines, with some reaching up to twelve. Most participants now use the device daily to read books, food labels, or street signs.
How the device works
Prima consists of two parts: an ultra-thin, wireless photovoltaic microchip implanted under the retina, and augmented reality glasses equipped with a small camera. The camera captures real-time images and projects them onto the chip using infrared light.
The 2x2 millimeter chip (roughly the size of a SIM card) acts as an artificial photoreceptor, converting the infrared signals into electrical impulses that the brain interprets as visual information. Because it's photovoltaic, the device requires no external power source or cables. This design allows users to combine their natural peripheral vision with the central vision generated by the implant, helping them navigate their surroundings more naturally.
Adjustments, training, and side effects
Patients began using the AR glasses four to five weeks after surgery. While some could detect patterns immediately, most needed months of visual training to refine their new sight, similar to rehabilitation seen with cochlear implants.
Nineteen of the 32 participants experienced side effects, including increased intraocular pressure, small retinal tears, or minor bleeding under the retina. All complications resolved within two months and were not life-threatening.
Next steps
Currently, Prima offers black-and-white vision only. The team is now developing software to distinguish grayscale tones, aiming to enable facial recognition and greater image depth.
"The first wish of participants was to read, but the next is to recognize faces," said Daniel Palanker, ophthalmology researcher at Stanford University and one of the project's lead authors. Future work will focus on improving image resolution, refining the design of the AR glasses, and testing the technology on other types of blindness caused by photoreceptor loss.