High Temporal Sub-millisecond Time Resolution Stimulation Increases Performances of Retina Prosthetic Vision

Abstract

Vision loss has an enormous impact on affected individuals, and increasing social and economics costs for the whole of society. Important approaches have been introduced, aimed at restoring visual functionality in the case of vision degradation and loss. Currently the most promising technology is represented by retinal implants, with companies producing devices approved for commercialization. The first clinical studies encouragingly reported perception elicited by both devices. Some patients retrieve autonomy, but only a few could reach satisfactory perception levels, allowing more complex tasks such as reading. Fundamental limitations however still exist in both spatial and temporal resolution, and these limitations call for improvements of the technology and of the stimulation strategies used therein. This study focuses on the importance of temporal resolution for retinal stimulation, and how it can be used to improve restored perception for implanted patients. We show a quantification of the improvement of discrimination performance when stimulating with high frame rates compared to conventional 30-60Hz frame rates. Such effect is evaluated using data collected from implanted patients, and deriving from it a realistic phosphene model. This study allowed to accurately replicate the perceptual effects of the studied technologies, and to evaluate the hypotheses regarding performance improvements using higher temporal resolutions for stimulation strategies in visual restoration devices.