methods for forming implantable composite keratoprostheses are provided . the methods provide keratoprostheses designed to provide a suitable substrate for corneal epithelial cell growth while maintaining the desirable characteristics of hydrogels , i . e ., clarity , flexibility and the ability to allow diffusive flow of nutrients . in a preferred embodiment the method includes placing corneal tissue in a mold having a corneal implant shape and crosslinking a polymeric solution to chemically bond a biocompatible hydrogel having a thickness between approximately 50 and 100 microns to the corneal tissue to form the keratoprosthesis . upon implantation , the corneal tissue abuts epithelial cells surrounding the keratoprosthesis . in another preferred embodiment , a polymer solution is placed between the corneal tissue and a pre - formed hydrogel and then polymerized so that the polymer solution couples to both the hydrogel and the corneal tissue .