Development of silicon-micromachined retinal tacks for artificial retina implantation

This paper reports fabrication results of silicon retinal tacks and preliminary test results of silicon-micromachined retinal tacks. It is mainly intended to fix a stimulating microelectrode array, which is a part of the implantable artificial retina system. Although conventional retinal tacks made of titanium are widely used, they are expensive, invasive and restricted in shape. Also, glues could cause degeneration of inner retina and fibrin formation. Silicon micromachining technology, based on semiconductor manufacturing, can produce retinal tacks in a mass. Furthermore, the tack is easily shaped and the shapes are highly reproducible. Various types of retina tacks are proposed and fabricated. Ex vivo experiment was done in enucleated porcine eyes and in vivo experiment was done in rabbit eyes. There were some points to be improved, but we found that the silicon tack was useful and could be a good candidate as the substitute for the conventional titanium tack.