DSAEK is a new method of performing corneal transplants on patients whose corneas begin to cloud overdue to endothelial dysfunction. The layer of cells that pump fluid from the back surface of the cornea inside the eye where the endothelium is located keeps the tissue clear. If the pump cells are not working properly the cornea swells and becomes replaced, and cloudy. An inherited disease called Fuchs’ dystrophy is the most common cause of endothelial dysfunction. In the DSAEK procedure, the full thickness cornea is not replaced and instead only the diseased pump cells are transplanted.