An implant of a bionic eye half the thickness of a human hair has helped people with irreversible vision loss see again, opening a potential ‘new era’ in tackling blindness.
Doctors who implanted the sim-shaped prosthetic devices say they helped many of the 38 elderly patients in the trial regain their ability to read letters, numbers and words.
“In the history of artificial vision, this represents a new era,” said Mahe Moquet, senior consultant at Moorfields Eye Hospital in London, one of the 17 participating sites.
“Blind patients are actually able to beneficially restore central vision, something that has never been done before. Regaining the ability to read is a huge improvement in their quality of life, lifts their mood and helps regain their confidence and independence.”
The experiment found that 84% of the participants were again able to read letters, numbers, and words after installing an implanted device called the Prima device.
Eye specialists hailed the results as “remarkable” and said the device could help people with the “dry” form of age-related macular degeneration (AMD), the leading cause of vision loss in people over 50.
Moorfields said: “The revolutionary new implant is the first ever device that enables people to read letters, numbers and words through a blind eye.”
All 38 patients had geographic atrophy with dry AMD, which over time progressively deprives a person of their sight and for which there is no cure. Most people with this condition lose some of their central vision, and in some cases it progresses to complete vision loss as cells in the macula die and the central macula dissolves.
They had all lost their central vision and had only limited peripheral vision before the device was implanted in an operation that lasted less than two hours. Five of them were treated at Moorfields and the others in hospitals in Germany, France, Italy and the Netherlands.
Sheila Wilson from Wiltshire, one of the people who had the chip implanted at Moorfields, said: “Before I had the implant, it was like having two black discs in my eye, with a deformity on the outside. I was an avid reader and wanted it back. There was no pain during the procedure but you are still aware of what is happening.
“It made a huge difference. It’s a new way of looking through your eyes, and it was very exciting when I started to see a message. It’s not simple, learning to read again, but the more hours I put in, the more I learn.”
The Prima device, an extremely fine chip measuring just 2mm x 2mm, is inserted under the center of the retina in a procedure known as a vitrectomy.
To help them see and write, patients were given augmented reality glasses that contained a video camera connected to a small computer, and were attached to a waist belt. It has included a zoom feature to make text larger and easier to read.
Patients can use the glasses to focus and scan the object in the displayed image that they want to read. The glasses project the viewer as a beam of infrared light through the chip, activating the device. The artificial intelligence in the waistband’s computer processes the information and turns it into an electrical signal, which passes through cells in the retina and optic nerve to the brain.
Moquette stressed that patients must undergo extensive training and rehabilitation of their eyes in order to realize the benefits of the technology.
“It’s not like you put a chip in your eye and then you can see again. You have to learn how to use that kind of vision,” he said.
The results of the experiment are reported in New England Journal of Medicine.