Safety assessment of one-month semichronic electrical stimulation by laser-processed stimulation electrode of artificial vision system

We have been developing an artificial vision system, which gives electrical stimulation to remaining retinal cells to restore vision. In this study, we gave electrical stimulation to the retinae of rabbits for one month by using femtosecond laserprocessed porous surface electrodes and unprocessed smooth surface electrodes in order to evaluate the performance of the stimulation electrode and study the safety relating to the effect of long-term electrical stimulation on their eyes. In this test condition, safety has been confirmed regardless of the porosity of electrode surface. In addition, the charge injection capacity of laser-processed electrodes was higher than that of unprocessed electrodes both before and after one month stimulation. It suggested that laser-processing enhanced the performance of electrodes and also safety of electrical stimulation to retinae.