Europe approves a retinal implant that helps AMD patients read

For people who have lost the middle of their vision, the most ordinary acts become hard: reading a line of text, filling in a crossword, checking a phone. More than 5 million people around the world have the advanced form of age-related macular degeneration called geographic atrophy, and until now no treatment could restore their sight. In July, the PRIMA system was approved in Europe. It is still awaiting FDA clearance in the United States.

The retina works in three layers. Photoreceptors turn light into an electrical signal, bipolar cells process that signal, and ganglion cells pass it to the optic nerve and the brain. In this disease, only the photoreceptors die; the layers behind them stay healthy. PRIMA was designed around that fact. The implant replaces the lost photoreceptors and sends visual information straight into the circuits that still work. Developed by Science Corporation in California, it is, in the words of Frank Brodie, an ophthalmologist at the University of California, San Francisco and the company's chief medical officer for ophthalmology, a way of "leveraging all of the body's own natural functions to process and transmit the information."

The chain runs through three pieces of hardware. Glasses fitted with a miniature front-facing camera record what the wearer sees, at roughly five megapixels and 30 frames per second, close to television quality. The raw video travels by fiber-optic cable to a small handheld processor, which turns it into infrared light signals and sends them back to the glasses. A laser projector on the glasses then shines pulses of near-infrared light at 880 nanometers, a wavelength the eye cannot see, through the pupil onto the implant. The implant carries 378 pixels, each with an electrode and two photovoltaic cells. Those cells convert the light into electrical current for the healthy cells behind them, and they also power the chip, so the implant needs no battery.

For patients, the change is from no option to one. In Europe the system now holds approval; in the US it is still waiting for the FDA, and the sources give no date for that decision. The reported gains are concrete: after training, more than 80% of recipients could read, complete crosswords and use their phones. The system treats one specific cause of vision loss, the blind spot created by advanced AMD, and the figures describe the people who reached those tasks, not every patient who is fitted with it.