The visual cortical prosthesis system is designed to bypass diseased or injured eye anatomy and to transmit these electrical pulses wirelessly to an array of electrodes implanted on the surface of the brain’s visual cortex, where it is intended to provide the perception of patterns of light.
Reviewed by Nader Pouratian, MD, PhD
A novel visual cortical prosthesis system (Orion, Second Sight Medical Products) is expanding the pool of patients who can benefit from artificial vision. Patients include not only those with retinal disease—such as retinitis pigmentosa, diabetic retinopathy, and glaucoma—but also those who have lost vision to eye injury or optic nerve injury/ disease and are ineligible for any other visual prosthetic.
The FDA recently approved the system for an Early Feasibility Study through its Breakthrough Device pathway—and the latest results at 12 months have been positive, said Nader Pouratian, MD, PhD, one of the study’s principal investigators.
“We need to realize that the goal of a system, such as [this], is not to restore vision as we know it in sighted individuals, but to restore visual perception to blind people to allow better function in and interaction with the world,” said Dr. Pouratian, associate professor of neurosurgery, Ronald Reagan UCLA Medical Center, Santa Monica, CA. “In achieving that goal, we are making huge progress.”
The visual cortical prosthesis system is designed to bypass the eyes and optic nerve, i.e., the diseased or injured tissue. Patients wear a miniature camera mounted on a pair of eyeglasses, an antenna, and a video processing unit (VPU).
The camera captures real-time images as processed by the VPU and then converted into stimulation patterns that are transmitted wirelessly to an electrode array implanted on the surface of the primary visual cortex. The system has 60 electrical contacts that deliver the stimulation to the brain, he noted.
The feasibility study is being conducted by Dr. Pouratian; Jessy D. Dorn, PhD, senior director of scientific research, Second Sight Medical Products; Robert Greenberg, MD, PhD, at UCLA, and at Baylor College of Medicine, Houston, where Daniel Yoshor, MD, is site director and also one of the principal investigators. Six subjects (five men, 1 woman; age range, 29-57 years), who became blind from disease or injury and had a normal visual cortex, participated and will be followed for 5 years.
Specifically, three patients suffered a trauma, two had glaucoma, and one had endophthalmitis. To now, the average time after implantation is about 12 months. During the first testing of the device after implantation, 2 weeks postoperatively, each electrical contact is turned on individually to determine at what level of stimulation results in a visual perception, i.e., phosphenes.
Nader Pouratian, MD, PhD
E: [email protected]
Dr. Pouratian is a consultant to Second Sight Medical Products.
Jessy D. Dorn, PhD
E: [email protected]
Dr. Dorn is an employee of Second Sight Medical Products.
Robert Greenberg, MD, PhD
Dr. Greenberg is a consultant to Second Sight Medical Products.