Aug 2017 optics.org
Second Sight, the California-based developer of visual prosthetics and retinal implants, will soon begin a feasibility clinical study to assess its Orion cortical visual prosthesis system in human patients, after receiving conditional approval from the US FDA. The terms of the approval allow two US sites, at the University of California at Los Angeles (UCLA) and Baylor College of Medicine in Houston, to enroll up to five patients in total. "This is an exciting milestone for the company, given the potential of Orion to provide useful vision to millions of blind individuals worldwide who have no other option today," said Will McGuire of Second Sight after the new FDA approval. "The Orion team has met all major internal milestones this year and we remain on-track to achieve the company's stated goal of implanting our first Orion patient before year end.”
Orion’s cortical visual prosthesis
Orion is intended to assist patients who experience profound visual impairment or who are completely blind. It is implanted into the surface of the brain near the visual cortex, which it stimulates directly with signals received from a wearable video camera and processed by a portable computer unit. This architecture bypasses the retina and the optic nerve altogether, in an analogous fashion to the principle behind cochlear implants as a treatment for deafness.
The approval follows Second Sight's first successful implantation and activation of a visual cortical stimulator in a human subject in October 2016, the initial proof-of-concept for development of the Orion system. In that UCLA study, a 30-year-old patient was implanted with a wireless multichannel neurostimulation system, and was able to perceive and localise individual spots of light with no significant adverse side effects.
Orion represents a significant step for Second Sight beyond its existing development of the Argus II retinal implant, intended for the treatment of Retinitis Pigmentosa and age-related macular degeneration, although the company has said that the new platform requires only relatively minor modifications from the existing product. The Argus II is an epiretinal implant, placed in the inner surface of the retina from where it directly stimulates the innermost ganglion cells and bypasses the retina's other layers. This avoids use of the damaged photoreceptors, instead utilising the still-healthy ganglions which transmit the visual information along the optic nerve.