Abstract
Abstract: :
Purpose: To evaluate the short and long-term safety and efficacy of a subretinal Artificial Silicon Retina (ASR) microchip in treating vision loss from retinitis pigmentosa Methods: A light-powered ASR microchip, 2-mm in diameter and producing electrical stimulation, was implanted into the subretinal space of 10 patients with retinitis pigmentosa. Pre- and postoperative objective and subjective assessment of visual function were performed and included testing of ETDRS letters, color perception, automated visual fields, ERGs and custom tests for motion detection and visual angle resolution. Postoperative visual function testing was conducted for greater than 2 1/2 years along with clinical and laboratory evaluation of chip function and safety. Results: ASR chips were readily implanted into the subretinal space of 10 patients and appear to be safely tolerated for at least 2 1/2 years in some patients with persistence of implant electrical activitiy. Visual function improvement, first noted at 2 to 6 weeks after surgery, was still present 2 1/2 years post implantation in the longest implant group and involved visual field areas distant from the implant. Conclusions: In this pilot study, subretinal ASR chips seem to be well tolerated in retinitis pigmentosa patients and appear to produce improved and persistent visual funciton possibly related to a neurotrophic effect.
Keywords: retinitis • retina • vitreoretinal surgery