Multiple research groups now theorize that tissue engineering will provide novel therapies for treating corneal endothelial cell (CEC) decompensation. In 2013, we initiated first-in-man clinical research (not an Investigational New Drug [IND] clinical trial) of a CEC injection therapy at the Kyoto Prefectural University of Medicine in Japan. In a clinical trial, cultured CECs (CECs) supplemented with a rho-associated protein kinase (ROCK) inhibitor were injected into the anterior chamber. In all of our first 11 cases, the corneal transparency was restored with the regeneration of a monolayer sheet structure of corneal endothelium. As proof of concept of CEC injection therapy was obtained, we are currently developing a cellular product to deliver this therapy to all patients. To that end, we have established an efficient cell culture protocol and ‘ready-to-use’ frozen cells. In this presentation, I will introduce the current status of our developments to provide a platform for discussing future therapies for treating corneal endothelial decompensation.