Geographic atrophy, an advanced stage of age-related macular degeneration (AMD), affects over 5 million individuals globally. The PRIMA system, approved in Europe last July and pending FDA authorization in the U.S., uses a retinal implant paired with camera-equipped glasses to enhance vision for those with severe AMD.
The PRIMA system works because AMD only destroys photoreceptors while leaving other retinal structures intact. Its retinal implant replaces these damaged cells, sending visual data straight through the remaining healthy neural pathways toward the brain.
“We’re leveraging all of the body’s own natural functions to process and transmit the information,” says Frank Brodie, an ophthalmologist at the University of California, San Francisco, and Science Corp.’s chief medical officer for ophthalmology.
A tiny front-facing camera mounted on special eyeglasses records the wearer’s view in real time, producing a video stream of about five megapixels at 30 frames per second, which is then sent through a fiber-optic link to an external processor.
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A compact, portable processor transforms the incoming video into infrared light pulses that travel back to the glasses; it also features physical controls allowing users to modify contrast, brightness, and zoom settings.
A laser projector on the glasses shines pulses of near-infrared light directly at the eye, passing through the pupil and on to the retinal implant in the back of the eye. The implant is made up of 378 pixels, each with an electrode and two photovoltaic cells. Specifically, the laser projector operates at a wavelength of 880 nanometers, which is an invisible wavelength, allowing it to shine pulses of near-infrared light directly at the eye without being visible to the wearer.
Each pixel’s photovoltaic cells generate electrical current from the light, which healthy bipolar and ganglion cells transmit to the brain, while also functioning as solar panels to power the implant without requiring a battery; post-training, over 80% of users regained abilities like reading, solving crosswords, and using smartphones.