Restoring vision — or at least improving it — for people suffering from macular degeneration may soon be possible with a tiny chip and special glasses.
Together, the chip and glasses help restore central vision for a type of eye disease known as age-related macular degeneration (AMD).
More than 80% of patients at trial sites in the United States, Germany, UK, Netherlands and Italy showed significant improvement in central vision after one year of monitoring.
With the implants, patients were able to read numbers and words at home and improve their reading ability by up to 25 letters – or five lines – on a standard eye test chart.
Most participants over the age of 50 lost about half of their vision from standard 20/20 vision.
“This is the first time it has been shown that vision can be restored in a blind retinal area that is important for daily life,” Frank Holz, head of the study and chair of ophthalmology at the University of Bonn, told DW.
As some people age, the macula, the part of the retina responsible for central vision, may deteriorate, causing first blurred vision and then continued deterioration. Atrophic AMD is a leading cause of vision loss in older people, affecting at least five million people globally.
Implant helps restore reading for people with atrophic AMD
A healthy eye can ‘see’ by receiving light from the outside world and converting it into electrical signals which are sent to the brain via the optic nerve for interpretation. Macular degeneration reduces the eye’s ability to do this.
The solution of implanting a pinhead-sized chip in the retina, which could compensate for this degradation, inspired Daniel Palankar, an ophthalmologist at Stanford University in the US. He collaborated with Jose-Alain Sahel, a French ophthalmologist based at the University of Pittsburgh School of Medicine, to develop the technology. They wanted to develop an implant that would remove the wires beneath the skin and hired Holtz to lead the latest trial.
But the chip is only half of what they call the “Prima” system.
The second part is a special set of glasses. They use a mounted camera to transmit visual data to the implant, which sends the data to a handheld processor for enhancement, and then receives high-quality imagery back.
The images are converted into electrical impulses and the remaining retinal cells are used to send information to the brain.
“In this disease, crucially, it is essential that the biocomputer, if you like – [biological] The wiring anterior to the chip – is still there,” Holz said, referring to the cells still functioning in the eye.
“If all the cells in the retina were dead, the chip would not work at all. It [the implant] Simply replaces the photoreceptor and basically converts light into electrical stimulation, which is what nature does in the eye with the retina.”
Collaboration and persistence pay off
Sahel and Stanford-based Palankar were working on different technologies to solve the same problem when they met at a conference in 2012.
They decided to pool their resources to develop the implant, first with smaller studies with many patients and then this larger trial with more than 30 patients.
But the current study nearly collapsed when the company developing Prima went out of business in 2024.
“I remember well those days a while ago, when the study was almost completed and everything was about to end,” Sahel told DW. “There may be a situation where you have a product that is working and there is no way to get it to people.”
The developer has since been acquired by the American company Science Corporation, which has taken over production and is seeking approval from the Food and Drug Administration (FDA) for use as a medical therapy in the US and CE certification for use in Europe.
By conducting trials across multiple countries and sites, the testing team hopes to achieve approval in both regions.
“You want to demonstrate that the technology is not limited to just one or two highly skilled surgeons,” Sahel told DW. “And it may also benefit patients from many backgrounds.”
It is an essential criterion for regulators that researchers show that a difficult operation like this transplant can be successfully performed by eye surgeons. Although some adverse effects were reported in some patients, these resolved by the end of the 12-month study period.
“Showing that there was some consistency in the results across 13 different sites and different surgeons gives us the potential to apply this to more centers and to be distributed to more patients,” Sahel said.
Chip implantation: not an easy operation
Both Sahel and Wood highlighted that the new technology has limitations. While the operation to implant the chip has now been successfully performed by several surgeons around the world, he told DW it was not an easy operation.
“This is a very complex surgery that requires good skills,” Sahel said.
The second challenge is the patients. There are logistical constraints that may affect a patient’s suitability, such as their ability to visit the clinic repeatedly for rehabilitation after surgery, and to receive support at home during this period.
Holz said the implant recipient must be prepared for constant post-surgery reviews, and be trained to use the cameras and processor to be able to use the implant successfully.
That rehabilitation program currently takes about 12 months.
Edited by: Zulfikar Abbani