Moran Eye Center, University of Utah
A former science teacher who has been blind for 16 years could see letters, distinguish objects at edges – and even play a Maggie Simpson video game – thanks to a visual prosthesis that includes a camera and a brain implant, according to American and Spanish researchers there. collaborated on the project.
The test subject had the implant for six months and experienced no disturbances in her brain activity or other health complications, according to a summary of the study published this week in Journal of Clinical Investigation.
The study promotes what it calls a “long-dreamed of scientists” to give blind people a rudimentary form of vision by sending information directly to the brain’s visual cortex.
“These results are very exciting because they show both safety and effectiveness,” said one of the leading researchers, Eduardo Fernández of Miguel Hernández University, in a statement. “We have taken a significant step forward and are showing the potential of these types of devices to restore functional vision for people who have lost their sight.”
A camera sends visual data directly to the brain
In the experiment, a neurosurgeon implanted a microelectrode array in the visual cortex of Berna Gómez, a former teacher who has been blind for more than 16 years. The implant was then paired with a video camera mounted in the center of a pair of glasses.
After a training period, Gómez was able to decipher visual information that was carried from the camera directly to her brain.
The training included a video game that helped Gómez learn to interpret the signals from the electrodes. In the game, a screen suddenly shows a picture of Maggie Simpson holding a gun in either her left or right hand. The player must correctly choose which hand is holding the weapon; using input from the matrix, Gómez learned how to succeed in this task.
At the time of the investigation, Gómez was 57 years old. Because of her participation, including her ability to provide clinically accurate feedback to the researchers, Gómez was named as co-author of the study.
Some of the effects of the prosthesis were limited; it let e.g. Gómez does not identify all the letters of the alphabet. But she “reliably discriminated some letters like” I “,” L “,” C “,” V “and” O “,” according to the study.
Further studies could use more electrodes to increase visual data
The microelectrode array was implanted through a “mini-craniotomy” in a process that researchers say “is straightforward and follows standard neurosurgical procedures.” It involves making a hole in the skull that measures 1.5 cm (slightly larger than half an inch).
The array is only 4 mm (about one-eighth of an inch) square, but it holds 96 electrodes. The researchers say that previous studies have found that about 700 electrodes could provide a blind person with sufficient visual information to increase their mobility to a useful extent. And because the implant required only small electrical currents to stimulate the visual cortex, they hope to add more microarrays in future experiments.
“One goal of this research is to give a blind person more mobility,” said Richard Normann, a researcher at the John A. Moran Eye Center at the University of Utah. “It could allow them to easily identify a person, doorways or cars. It could increase independence and security. That’s what we’re working on.”
ONE clinical trials related to the study is scheduled to continue in May 2024. The research is funded through several entities, including the Spanish Ministry of Science and Innovation and Miguel Hernández University as well as the Moran Eye Center.
The method of completely bypassing the eyes can one day restore sight to about 148 million people worldwide – this is how many people have had the connection between their eyes and their brain disconnected, due to conditions such as glaucoma or optic nerve atrophy.
The approach used by researchers from Utah and Spain is similar to that hailed last year when researchers said they were able to get volunteers to see letters by sending electricity through electrodes on the surface of the brain.
Visual impairment is one of the most common disabilities in the world, and researchers are using several strategies to help people affected by it. In another recent success, researchers used the CRISPR gene editing tool to alter DNA in humans to help them fight a rare genetic eye disease.