Scientists used a tiny brain implant to help a blind teacher see letters again
A former science teacher who's been blind for 16 years
became able to see letters, discern objects' 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 who collaborated
on the project.
The test subject had the implant for six months and
experienced no disruptions to her brain activity or other health complications,
according to an abstract of the study that was published this week in The
Journal of Clinical Investigation.
The study furthers what it calls a "long-held dream of
scientists," to impart a rudimentary form of sight to blind people by
sending information directly to the brain's visual cortex.
"These results are very exciting because they
demonstrate both safety and efficacy," said one of the lead researchers,
Eduardo Fernández of Miguel Hernández University, in a statement. "We have
taken a significant step forward, showing the potential of these types of
devices to restore functional vision for people who have lost their vision."
A camera sends visual data directly to the brain
In the experiment, a neurosurgeon implanted a microelectrode
array into 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 fed from the camera directly to her brain.
The training included a video game that helped Gómez learn how to interpret the signals coming from the electrodes. In the game, a screen suddenly shows an image of Maggie Simpson holding a gun, in either her left or right hand. The player must correctly select which hand holds the weapon; using input from the array, Gómez learned how to succeed in that task
At the time of the study, Gómez was 57 years old. Because of
her participation, including her ability to give clinically precise feedback to
the scientists, Gómez was named as a co-author of the study.
Some of the prosthesis' effects were limited; it did not let
Gómez identify all letters of the alphabet, for instance. But she
"reliably discriminated some letters such as 'I,' 'L,' 'C,' 'V' and 'O,'
" according to the study.
Further studies could use more electrodes to boost visual
data
The microelectrode array was implanted through a
"minicraniotomy," in a process that the researchers say "is
straightforward and follows the standard neurosurgical procedures." It
involves making a hole in the skull measuring 1.5-cm (a bit larger than half an
inch).
The array is just 4 mm (about an eighth of an inch) square,
but it holds 96 electrodes. The researchers say previous studies have found
around 700 electrodes could give a blind person enough visual information to
boost their mobility to a useful extent. And because the implant required only
small electrical currents to stimulate the visual cortex, they're hoping to add
more microarrays in the 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 identify a
person, doorways, or cars easily. It could increase independence and safety.
That's what we're working toward."
A clinical trial related to the study is scheduled to
continue through May of 2024. The research is being funded through several
entities, including Spain's Ministry of Science and Innovation and Miguel
Hernández University, as well as the Moran Eye Center.
The method of bypassing the eyes altogether could someday
restore vision to roughly 148 million people worldwide that's how many people
have had the link between their eyes and their brain severed, the researchers
say, due to conditions such as glaucoma or optic nerve atrophy.
The approach used by the researchers from Utah and Spain is similar to one that was hailed last year, when scientists said they were able to get volunteers to see letters by sending electricity through electrodes on the brain's surface.
Visual impairment is one of the most common disabilities in
the world and scientists are employing several strategies to help people who
are affected by it. In another recent success, scientists used the CRISPR
gene-editing tool to modify DNA in people to help them combat a rare genetic
eye disease.
This article has not been edited by Blueplanet staff
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