High Resolution Photovoltaic Retinal Prosthesis

描述(申请人提供)：视网膜退行性疾病导致失明，因为失去了“图像捕捉”光感受器层，而“图像处理”视网膜内层的神经元在很大程度上被保存下来。电子视网膜假体试图通过电模式刺激存活的神经元来恢复视力。最近证实了第一个视网膜假体的非常令人鼓舞的临床结果。然而，电流植入物是通过感应线圈供电的，需要复杂的外科方法来植入线圈-解码器-电缆-阵列系统，该系统通过眼内电缆向刺激电极输送能量。我们开发了一种光伏视网膜下假体，其中每个像素的硅光电二极管直接将视频护目镜投射的脉冲近红外(NIR)图像转换为局部电流来刺激神经元。与其他设计相比，该系统具有多项优势：由于无线激活植入物中的像素，系统可扩展到数千个电极；它保持了眼睛运动和图像感知之间的自然联系；植入大大简化，植入物的模块化设计允许通过平铺扩大视野；柱状电极允许细胞规模接近目标神经元。这种多功能系统可以用来满足各种形式的视网膜变性患者的不同需求。我们已经制造并测试了第一代植入物。光伏阵列表现出长期的生物相容性，并在体外和体内提供安全的近红外脉冲照射下的视网膜刺激。我们现在寻求生产设计为最高分辨率和最低刺激阈值的植入物，并通过惰性和生物相容性涂层保护长期植入物。为了实现这些目标，我们将评估不同设计的视网膜下光伏植入物在体外和体内对正常和退化视网膜的动物的视力和对比敏感度。这个项目 汇集了工程师、神经科学家和眼科医生的独特组合，完成了专门为实现视觉功能水平而设计的高分辨率视网膜假体系统的开发和评估。

DESCRIPTION (provided by applicant): Retinal degenerative diseases lead to blindness due to loss of the "image capturing" photoreceptor layer, while neurons in the "image processing" inner retinal layers are preserved to a large extent. Electronic retinal prostheses seek to restor sight by electrical pattern stimulation of surviving neurons. Very encouraging clinical results with the first retinal prostheses have been recently demonstrated. However, current implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems, which deliver energy to stimulating electrodes via intraocular cables. We developed a photovoltaic subretinal prosthesis, in which silicon photodiodes in each pixel directly convert pulsed near-infrared (NIR) images projected from video goggles into local electric currents to stimulate neurons. This system offers multiple advantages over other designs: due to wireless activation of the pixels in the implant the system is scalable to thousands of electrodes; it maintains the natural link between eye movements and image perception; the implantation is greatly simplified and modular design of the implant allows expanding the visual field by tiling; pillar electrodes allow cellular-scale proximity to the targe neurons. Such a versatile system could be used to address the divergent needs of patients with various forms of retinal degeneration. We have manufactured and tested the first generation of the implants. Photovoltaic arrays show long-term biocompatibility, and provide safe retinal stimulation upon illumination with NIR pulses in-vitro and in-vivo. We now seek to produce the implants designed for highest resolution and lowest stimulation thresholds, and protected by inert and biocompatible coatings for long-term implantations. To achieve these goals we will assess visual acuity and contrast sensitivity obtained with subretinal photovoltaic implants of different designs in-vitro and in-vivo in animals with normal and degenerate retinas. This project brings together a unique combination of engineers, neuroscientists and ophthalmologists to complete the development and evaluation of a high-resolution retinal prosthetic system designed specifically for achieving the functional levels of vision.