Endothelial bioengineering is the simplest form of corneal bioengineering insofar as it consists of producing a large quantity of corneal endothelial cells and packaging them in a form that can be transplanted to the patient. It seems to be the most realistic solution to replace endothelial grafts made from donor corneas and thus allow, by domino effect, to reserve them for other indications of keratoplasty. Kyoto ophthalmologists (S Kinoshita, N Koizumi and N Okumura) were the pioneers of injection therapy by demonstrating its feasibility and safety, with an efficacy at 5 years comparable to that of conventional endothelial grafts. These pioneers, split into two distinct entities, are currently industrializing this therapy by injecting cells in suspension, in the USA (Aurion biotech) and in Asia (Actualeyes). In addition to injections, tissue engineered endothelial keratoplasty (TEEK) is a complementary research approach. They consist in reproducing in vitro grafts of the DMEK or DSAEK type by seeding the cultured cells on a ‘corneo-compatible’ support. Several have passed the preclinical stages and one is in clinical trial in Asia. Suspension cells and TEEK each have advantages and limitations that make them complementary in the management of corneal endothelial diseases.

We will analyze why there is not yet an alternative process for mass production of corneal endothelial cells or clinical grade TEEK, systematically detailing the various bottlenecks identified, from the source of cells and media, to regulatory and economic aspects.