Alternatives to endokeratoplasty: an attempt towards reducing global demand of human donor corneas

The cornea is an anterior transparent tissue of the eye that enables the transmission of surrounding light to the back of the eye, which is essential for maintaining clear vision. Corneal endothelial diseases can lead to partial or total blindness; hence, surgical replacement of the diseased corneal tissue with a healthy cadaveric donor graft becomes necessary when the endothelium is damaged. Keratoplasties face a huge challenge due to a worldwide shortage in the supply of human donor corneas. Hence, alternative solutions such as cell or tissue engineering-based therapies have been investigated for reducing the global demand of donor corneas. This review aims at highlighting studies that have been successful at replacing partial or total endothelial keratoplasty. Plain language summary The cornea is an important tissue, as it allows the transmission of surrounding light to the back of the eye. The posterior layer of the cornea is made up of hexagonal endothelial cells that help maintaining the required transparency. Corneal endothelial cells do not have a natural regenerative capacity; therefore, if damaged, they must be replaced by healthy donor tissue. It is difficult to obtain human donor corneas; hence, researchers have attempted to grow endothelial cells using specific drugs that allow these cells to grow in the lab. In this review, we highlight the application of lab-grown cells in animal and human studies with ongoing clinical trials of other drugs and techniques to replace the need of human donor tissues.