The Moran|Cortivis Prosthesis, which uses the Utah Electrode Array, has now been tested on three individuals with blindness.
Scientists from Spain’s Miguel Hernandez University and the John A. Moran Eye Center at the University of Utah have now used an experimental prosthesis hardwired into the visual regions of the brain to safely provide a form of artificial vision to three individuals with blindness.
Spanish neuroscientist Eduardo Fernández, MD, PhD, and Utah’s Richard A. Normann, PhD, published in 2021 results of experiments with the prosthesis conducted with a 60-year-old woman. The prosthesis, which uses the Utah Electrode Array (UEA) developed by Normann to stimulate neurons in the brain’s visual cortex, enabled the woman to identify lines, shapes, and simple letters evoked by different patterns of stimulation.
Speaking at a symposium held at the Moran Eye Center on Thursday, Fernández announced he has now achieved similar results in two additional study participants.
His latest experiments have gone one step further to test whether the prosthesis can provide a form of vision useful for the blind. In one video shown to the audience, a man wears the prosthesis while independently navigating down a sidewalk and around people. In another, he avoids objects while walking on a treadmill in front of a virtual reality video screen.
“This provides a ‘proof of concept,’ and the stage is now set for more work in this area and for developing engineering technologies to transform this prototype into a clinical system,” said Normann, Distinguished Emeritus Professor of Bioengineering and Ophthalmology and Visual Sciences at the University of Utah.
An adjunct professor at the Moran Eye Center, Fernández said he is preparing to recruit a fourth patient.
“We’re still only at the beginning of possibilities this prosthesis might provide,” he told audience members.
Among the challenges he will continue to address are increasing the visual field for the device and creating a bi-directional link to the brain.
How Does it Work?
Just 4 mm by 4 mm, one UEA is implanted into the brain of a study participant who then works with researchers for six months to test the prosthesis before the UEA is removed.
Participants wear eyeglasses equipped with a miniature video camera; specialized software encodes the visual data collected by the camera and sends it to the UEA. The array then stimulates neurons to produce phosphenes, perceived as white points of light, to create an image.
Normann and colleague Gregory Clark, PhD, first used a variant of the UEA in amputees to evaluate its safety and efficacy. The UEA allowed the amputees to control artificial limbs simply with their desire to move a finger or hand. The Spanish experiments were the first to implant the UEA into the visual cortex of blind human volunteers.
The research to date has used just one UEA, but in the future, Fernández would like to implant several UEAs into the visual cortex to produce a more complicated form of artificial vision. Earlier published research conducted by Normann indicates between seven and 10 arrays in the visual cortex, working together, could produce more detailed images.