Preliminary experimental results with the Moran|Cortivis Prosthesis support efforts to restore useful vision for the blind.
Newly published research details how a team of scientists from the John A. Moran Eye Center at the University of Utah and Spain鈥檚 Miguel Hernandez University successfully created a form of artificial vision for a blind woman using a prosthesis hardwired into her brain.
Publishing "" in The Journal of Clinical Investigation, Moran and University of Utah biomedical engineering researcher Richard A. Normann, PhD, and Spanish collaborator Eduardo Fern谩ndez, MD, PhD, detail how the Moran|Cortivis Prosthesis produced a simple form of vision for 60-year old Berna G贸mez.
The team conducted a series of experiments with G贸mez for six months in Elche, Spain, that represent a leap forward for scientists hoping to create a visual prosthesis that could increase independence for the blind.
A neurosurgeon implanted a microelectrode array invented by Normann, the Utah Electrode Array (UEA), into the visual cortex of G贸mez to record and stimulate the electrical activities of neurons.
G贸mez wore eyeglasses equipped with a miniature video camera; specialized software encoded the visual data collected by the camera and sent it to the UEA. The array then stimulated neurons to produce phosphenes, perceived by G贸mez as white points of light, to create an image.
A former science teacher fully blind for 16 years at the time of the experiments, G贸mez had no complications from the surgery and researchers determined that the UEA did not impair the function of neurons in close proximity to the electrodes or affect the function of the underlying cortex. G贸mez was able to identify lines, shapes, and simple letters evoked by different patterns of stimulation.
To help her practice using the prosthesis, researchers created a video game for G贸mez to play using a character from the popular television show The Simpsons. Thanks to her precise descriptions of visual perceptions and importance to the research, G贸mez is a co-author on the study.
In some experiments, researchers made electrophysiological recordings like this one below during electrical stimulation via the Utah Electrode Array. Overall, 74.7% of stimulation trials that evoked an increase in the activity recorded around the electrodes (either by stimulating a single electrode or several electrodes simultaneously) were associated with a reported visual perception.
"These results are very exciting because they demonstrate both safety and efficacy," said Fern谩ndez, who has collaborated with Normann for more than 30 years and is an adjunct professor at Moran. "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."
Normann and colleague Gregory Clark, PhD, first used 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 Spain experiments were the first to implant the UEA into the visual cortex.
The team鈥檚 neurosurgeon placed just one 4 mm by 4 mm UEA in G贸mez鈥檚 brain, but published research conducted by Normann indicates between seven and 10 arrays in the visual cortex, working together, could produce more detailed images for useful vision. University of Utah neurosurgeons and neuroscientists, John D. Rolston, MD, PhD, and Tyler Davis, MD, PhD, collaborated on the research.
"One goal of this research is to give a blind person more mobility," said Normann, Distinguished Emeritus Professor of Bioengineering and Ophthalmology and Visual Sciences at the University of Utah. "It could allow them to identify a person, doorways, or cars easily. It could increase independence and safety. That鈥檚 what we鈥檙e working toward."
The research team hopes the next set of experiments will use a more sophisticated image encoder system, capable of stimulating more electrodes simultaneously to reproduce more complex visual images.
Authors on the paper are: Eduardo Fern谩ndez, Arantxa Alfaro, Cristina Soto-S谩nchez, Pablo Gonzalez-Lopez, Antonio Lozano, Sebastian Pe帽a, Maria Dolores Grima, Alfonso Rodil, Bernardeta G贸mez, Xing Chen, Pieter R. Roelfsema, John D. Rolston, Tyler S. Davis, and Richard A. Normann.
Funding was provided by grant RTI2018-098969-B-100 from the Spanish Ministerio de Ciencia Innovaci贸n y Universidades, by grant PROMETEO/2019/119 from the Generalitat Valenciana, by the Bidons Egara Research Chair of the University Miguel Hern谩ndez, by the John A. Moran Eye Center at the University of Utah, the University of Utah Department of Neurosurgery, and by an unrestricted grant from Research to Prevent Blindness, New York, NY, to the Department of Ophthalmology and Visual Sciences, University of Utah.