Abstract
There are two main approaches in retinal prosthesis, where the electrodes are either implanted in epiretinal or subretinal space. In the subretinal prosthesis, retinal ganglion cells (RGCs) are activated by electrical stimulation of the retinal neural network. The aim of this mini-review is to assess the efficacy of silicon-based solar cells in evoking RGC responses by electrically stimulating neurons from the subretinal side. Using a silicon chip that consisted of a 4 × 4 microphotodiode array, we have recently shown that low light power (equivalent to 39 μC/cm2) can successfully evoke spiking responses of RGCs in an isolated rabbit retina. The reliable activation of RGCs by electrical stimulation in vitro using a microphotodiode array demonstrates the feasibility of developing solar cell based subretinal prostheses, which potentially could be developed into a power free device able to restore vision.