Hybrid Optogenetic and Electrical Stimulation of Retinal Ganglion Cells for Artificial Vision

Abstract Millions of adults worldwide experience severe visual impairment due to photoreceptor loss from retinal diseases such as retinitis pigmentosa and macular degeneration. Retinal prostheses that provide artificial vision by stimulating the surviving retinal ganglion cells (RGCs) have emerged as a promising therapy. However, all clinically approved retinal prostheses that use electrical stimulation face the issue of electrical spread. As such, no device has been able to provide vision restoration beyond the threshold of legal blindness. Optogenetic approaches provide greater spatial precision, however, they have poor temporal fidelity compared to electrical stimulation. Questions remain over the safety of the high intensity light required. Here, we developed an opto-electrical hybrid approach that reduced optogenetic activation thresholds and increased the high frequency sensitivity of opsin expressing RGCs. Our findings suggest that incorporating hybrid stimulation in future retinal prostheses could dramatically improve high resolution vision.