Breakthrough: A Wireless Eye Chip Is Helping People with Macular Degeneration Read Again

A revolutionary wireless eye implant has restored functional vision to people with advanced age-related macular degeneration, allowing them to read books and navigate subway signs for the first time in years. In a Stanford Medicine-led clinical trial, 27 out of 32 participants regained the ability to read within a year of receiving the device called PRIMA.

How Does This Eye Prosthesis Actually Work?

The PRIMA system consists of two main components that work together to bypass damaged photoreceptors in the eye. A small camera mounted on special glasses captures images and projects them in real time using infrared light to a 2-by-2-millimeter wireless chip implanted in the back of the eye. The chip then converts these images into electrical signals, effectively replacing the natural light-sensitive cells that macular degeneration has destroyed.

"All previous attempts to provide vision with prosthetic devices resulted in basically light sensitivity, not really form vision," said Daniel Palanker, PhD, a professor of ophthalmology and co-senior author of the study. "We are the first to provide form vision."

What Results Did Patients Experience?

The clinical trial included 38 patients older than 60 who had geographic atrophy, an advanced form of age-related macular degeneration with vision worse than 20/320 in at least one eye. The results were remarkable:

• Reading Ability: 27 out of 32 patients who completed the trial could read again after one year
• Visual Improvement: 26 participants showed clinically meaningful improvement, defined as reading at least two additional lines on a standard eye chart
• Average Progress: Participants improved by 5 lines on average, with one person improving by 12 lines
• Enhanced Vision: With digital enhancements like zoom and higher contrast, some participants achieved vision equivalent to 20/42

The device allows patients to use their natural peripheral vision alongside the prosthetic central vision, which helps with orientation and navigation. "The fact that they see simultaneously prosthetic and peripheral vision is important because they can merge and use vision to its fullest," Palanker explained.

What's Next for Vision Restoration Technology?

Currently, the PRIMA device provides only black-and-white vision, but researchers are developing software to enable full grayscale vision. "Number one on the patients' wish list is reading, but number two, very close behind, is face recognition," Palanker noted. "And face recognition requires grayscale."

Future versions of the chip will offer dramatically higher resolution. The current chip has 378 pixels that are 100 microns wide, but the next generation being tested in rats may have pixels as small as 20 microns wide with 10,000 pixels per chip. This could potentially give patients 20/80 vision, and with electronic zoom, they could achieve close to 20/20 vision.

Meanwhile, other promising treatments are advancing through clinical trials. Gene therapies for wet age-related macular degeneration (AMD) are showing particular promise, with three candidates in late-stage trials. The most advanced, ABBV-RGX-314, produced stable or improved visual acuity over two years in early trials, with most patients not requiring additional injections during that period.

For dry AMD, several innovative approaches are being tested, including drugs that can be self-administered at home. Elamipretide, a once-daily injection that patients give themselves under the skin, showed that nearly 15% of people experienced improved vision after 48 weeks, compared to just 2% who received a placebo.

The PRIMA breakthrough represents the first eye prosthesis to restore functional sight to patients with incurable vision loss, offering hope to the over 5 million people globally affected by geographic atrophy. As Palanker reflected on the 20-year journey from concept to reality: "The device we imagined in 2005 now works in patients remarkably well."