Optogenetic approaches to retinal prosthesis

Abstract

The concept of visual restoration via retinal prosthesis arguably started in 1992 with the discovery that some of the retinal cells were still intact in those with the retinitis pigmentosa disease. Two decades later, the first commercially available devices have the capability to allow users to identify basic shapes. Such devices are still very far from returning vision beyond the legal blindness. Thus, there is considerable continued development of electrode materials, and structures and electronic control mechanisms to increase both resolution and contrast. In parallel, the field of optogenetics—the genetic photosensitization of neural tissue holds particular promise for new approaches. Given that the eye is transparent, photosensitizing remaining neural layers of the eye and illuminating from the outside could prove to be less invasive, cheaper, and more effective than present approaches. As we move toward human trials in the coming years, this review explores the core technological and biological challenges related to the gene therapy and the high radiance optical stimulation requirement.

Optogenetic Approaches to Restoring Vision

“…To achieve better outcomes, the optogenetic approaches need to be combined with an extraocular imaging device or goggles (for a detailed review, see Barrett et al 2014). The extraocular device would include a camera and an image processing and/or display system.…”

Overview on Research and Clinical Applications of Optogenetics

“…These studies were expanded to restore functional vision in genetically blind rats using the same approach (Tomita et al, 2010). Since then, a number of groups have achieved similar results in different models using different promoters and opsins (see review by Barrett et al, 2014). In 2015 the FDA granted clearance for retinal injections of AAV expressing ChR2 to treat retinitis pigmentosa, which resulted in the first transfer of opsins to humans in 2016.…”

Miniaturized optogenetic neural implants: a review

“…These merits of optogenetics have opened a new door for neuroscientists to study brain mapping 13,14 , retinal prosthesis 15 , physiology disorder 16 , Parkinson's disease, epilepsy 17 , and cardiac electrophysiology 18 , which cannot be achieved using conventional electrical stimulation modality. Current progress toward the development of optogenetic tools has followed two parallel paths, one focusing on the development of light-gated microbial opsins for the genetic modification of normal neurons and the other on the development of optics and photonics for light delivery.…”