Long-Term Results from an Epiretinal Prosthesis to Restore Sight to the Blind

Abstract

Purpose Retinitis Pigmentosa (RP) is a group of inherited retinal degenerations leading to blindness due to photoreceptor loss. A rare disease, it affects about 100,000 people in the United States. There is no cure and no approved medical therapy to slow or reverse RP. The purpose of this clinical trial was to evaluate the safety, reliability, and benefit of the Argus® II Retinal Prosthesis System (Second Sight Medical Products, Inc., Sylmar, CA) in restoring some visual function to subjects completely blind from RP. Herein, we report clinical trial results at 1 and 3 years post-implant. Design The study is a multicenter, single-arm, prospective clinical trial. Subjects There were 30 subjects in 10 centers in the U.S. and Europe. Subjects served as their own controls – i.e., implanted eye vs. fellow eye, and System ON vs. System OFF (native residual vision). Methods The Argus II System was implanted on and in a single eye (typically the worse-seeing eye) of blind subjects. Subjects wore glasses mounted with a small camera and a video processor that converted images into stimulation patterns sent to the electrode array on the retina. Main Outcome Measures The primary outcome measures were safety (the number, seriousness, and relatedness of adverse events) and visual function, as measured by three computer-based, objective tests. Results Twenty-nine out of 30 subjects remained implanted with functioning Argus II Systems at 3 years post-implant. Eleven subjects experienced a total of 23 serious device- or surgery-related adverse events. All were treated with standard ophthalmic care. As a group, subjects performed significantly better with the System ON than OFF on all visual function tests and functional vision assessments. Conclusions The three-year results of the Argus II trial support the long-term safety profile and benefit of the Argus II System for patients blind from RP. Earlier results from this trial were used to gain approval of the Argus II by the FDA and a CE Mark in Europe. The Argus II System is the first and only retinal implant to have both approvals.

Silicon-Integrated High-Density Electrocortical Interfaces

“…Thus far, titanium-, glass-or ceramicbased enclosures have been the primary means for hermetic sealing in long-term implants, since these hard materials have been shown to be biocompatible and impermeable to water [181]. Even though such hard enclosures are used in the majority of long-term implants [6], [111], [122], [150]- [155], [159], [183], their very large volume and weight, typically much larger than the ICs and supporting components they contain, prohibits their use in high-dimensional neural interfaces heavily constrained by anatomical space such as retinal prostheses [184] and ECoG arrays [30]. In addition, hard packaging requires intricate methods for hermetic sealing of feedthroughs to polymer insulated extensions of the implant such as electrode array cabling, limiting the density of electrode channels due to feedthrough channel spacing requirements.…”

In Vitro and In Vivo Long-term Electrochemical Properties of Electrodes with Femtosecond-laser-induced Porosity for Visual Prostheses Based on Suprachoroidal Transretinal Stimulation

“…[1][2][3][4][5][6]. This animal study was approved by the Institutional Animal Care and Use Committee of Nidek Co., Ltd. All in vivo experiments were conducted in accordance with the Association for Research in Vision and Ophthalmology (ARVO) Statement for the Use of Animals in Ophthalmic and Visual Research.…”

“…Some visual prostheses have already been successfully used in clinical applications. Retinal prostheses can be classified into epiretinal, (2) subretinal,…”

Let There Be Light: Gene and Cell Therapy for Blindness

“…In these cases, new strategies for vision restoration should be explored. These include retinal prostheses-designed to stimulate responses from surviving inner retinal neurons [85][86][87] -or optogenetics, a technique allowing control of neural activity via genetic introduction of light-sensitive proteins such as channelrhodopsin and halorhodopsin. [88][89][90][91] Vertebrate opsins such as melanopsin 92 and rhodopsin, 93,94 as well as a chimera between melanopsin and mGluR6 receptor, 95 have also been used for vision restoration in latestage RP.…”