Researchers have found that an eye implant chip is able to not only restore vision in patients with damage to their sight, but can also integrate with their peripheral vision.
Scientists from Stanford first put the chip into eyeballs two years ago, but have now seen results beyond what they originally expected. A follow-up study was published in the journal Nature Communications.
Researchers expected the chip to restore sight, but did not think it was possible to also incorporate peripheral vision. To test whether a person’s peripheral vision was active, scientists had patients identify coloured lines that were placed to the side of their sightlines.
Previously, patients had a rather distorted perception of sight, Daniel Palanker, lead author of the study, said in a statement, adding that the new discovery is very exciting.
The chip almost acts as a camera sensor in the eye, picking up a digital image with a resolution that would mimic a person with a vision acuity of 20/460 — just enough to read large letters.
“This is an exciting proof of concept,” Palanker said. “However, to make it a really useful device and applicable to many patients, we need to improve resolution.”
The team of researchers is now working on an improved chip that aims to reach an acuity of 20/100.
Palanker developed the chip to specifically tackle macular degeneration, a condition that develops when cells in the middle of the retina degenerate. Standard treatments such as drugs target blood vessels that can block parts of the eye can slow the process of macular degeneration, but cannot stop it.
A total of 200 million people around the world are impacted by macular degeneration, the majority being 60 or older. Common symptoms include difficulty reading or recognizing people.
Almost 20 years ago, Palanker had the idea to develop a sight-restoring prosthesis. He and his team built a set of glasses with something like a video camera attached that would transmit a video signal into a chip in the eye. The cameras replaced photoreceptors — what we have in our eyes that help us see — with pixels, Palanker said.
Macular degeneration typically affects the middle of someone’s vision, according to the Mayo Clinic. Peripheral vision mostly remains intact. It’s also possible that if macular degeneration affects only one eye, you won’t even notice, as your good eye will compensate for the bad.
It isn’t exactly known what causes macular degeneration, but it could be brought on by smoking, obesity, and a person’s diet, as well as hereditary or environmental factors.
Two types of macular degeneration
There are two forms of age-related macular degeneration, wet or dry.
Dry is more common, but less severe, and occurs when the macula — an area in the centre of the retina that helps you clearly see details, like faces and text —becomes thinner over time. Wet is less common, affecting only one out of every 10 people with the disease. It causes blood vessels to swell and the macula to grow. If left untreated, it’s possible that blood can leak into the eye.
Approximately 1.4 million people in Canada have age-related macular degeneration, according to fightingblindness.ca. The organization recommends that people with early stage dry macular degeneration eat a variety of foods such as fish or vegetables, which could help slow the condition’s progression. Regular exercise is also recommended.
Chris Arnold is a Toronto-based writer.