Early Feasibility Study of a Neurostimulator to Create Artificial Vision

Abstract

Abstract INTRODUCTION Stimulation of human visual cortex is known to elicit visual perceptions that could potentially be used for creating artificial vision. The Orion Visual Cortical Prosthesis is a new device that is intended to restore some functional vision to blind patients. METHODS The device comprises an implant (consisting of an electronics package, receiving antenna, and an electrode array with 60 electrodes); glasses with a video camera; and a video processing unit (VPU). The camera collects real-time visual information, which is then processed by the VPU and converted to stimulation patterns sent to electrode array. The electronics are skull mounted with the subdural array implanted through a posterior interhemispheric approach. This is a 5-yr study of subjects who are bilaterally blind with bare light or no light perception due to non-cortical etiology. RESULTS A total of 6 subjects have been implanted in 2 centers. As of May 1, 2019, average implant duration was 11.1 mo (range 3.4-15.0 mo). Average age at time of implant was 50.3 yr. Cause of blindness included trauma (2), pediatric glaucoma (2), optic neuropathy (1), and endophthalmitis (1). One serious adverse device event (seizure) has been reported. Average thresholds ranged from 1.6 to 3.7 mA across the 6 subjects. At 6 mo postimplant, 3 of 5 subjects performed significantly better with the system on than off on a light localization task; 2 subjects performed better on a direction of motion task, and no subjects had measurable visual acuity. All 5 subjects were rated as receiving “positive” or “mild positive” benefit on a functional vision assessment. One-year adverse event and visual performance data for the first 5 subjects will be presented and compared to results from a commercially-available retinal prosthesis. CONCLUSION Safety and performance results of the first 5 subjects as of 6 mo postimplantation appear encouraging.