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History of Japanese Project of Artficial Vision
About Artificial Retina
Research Groups of Artificial Vision
Japanese Projects for Artificial Vision
Development of Surgical Techniques for Implantaion/Assessment of Biocompatibility
Development of Medium Size Animal Model
Functional Assesment/Neuroprotection
Functional analysis, in vitro, in vivo
Development of Electrode/Total System
Functional Evaluation and Neuroprotection
Projects for Artificial Vision


Dept of Visual Science,Osaka University
Functional Assessment of Multi-Channel Electrode Arrays using STS Electrical Evoked Potentials in Rabbits
Electrical Evoked Potentials (EEPs) were recorded with relatively low current intensities (less than 100 μA) using multi-channel electrodes by the STS method .Rabbit. EEPs were recorded even 3 weeks after chronic implantation.

Functional Assessment of Residual Retinal Ganglion Cells by Transcorneal Electrical Stimulation
We have developed a new method to assess the function of residual retinal ganglion cells (RGCs) by Transcorneal Electrical Stimulation (TES) and applied this to select patients with retinitis pigmentosa (RP). With electrical stimulation of the retina by TES, phosphenes and pupillary responses were observed. By measuring the threshold current for phosphenes and pupillary responses, we were able to estimate the extent and density of residual RGCs. We have started to screen candidates for an artificial retina with this method.

Department of Physiology, Osaka University
Functional Evaluation of Visual Prosthesis
Newly developed electrodes and systems should be evaluated with in vivo animal studies. We have evaluated the visual information obtained by Suprachoroidal Transretinal Stimulation (STS) with electrophysiological recording from the visual center of rats or cats. This will provide us with information for improving the STS-based artificial vision, especially finding out safer and more effective parameters as well as understanding STS-evoked sensations.

Basic Research on Neuroprotection by Electrical Stimulation
We have shown that electrical stimulation can promote the survival of axotomized retinal ganglion cells of adult rats. About one-half of axotomized retinal ganglion cells die by one week after optic nerve transection.
However, electrical stimulation of the stump of a transected optic nerve improves the survival rate of the retinal ganglion cells to more than 80%. We are now investigating this neuroprotective effect of electrical stimulation especially from the viewpoint of basic research.