The cornea is the clear covering of the front of the eye which bends, or refracts, light rays as they enter the eye. For clear vision to occur, the cornea must have the correct shape and clarity to focus incoming light rays precisely on the retina at the back of the eye. When the cornea becomes cloudy or misshapen from injury, infection or disease, transplantation may be recommended to replace it.
There are several different corneal transplant procedures available to help restore vision in patients with corneal problems. The traditional corneal transplant procedure involves replacing the entire damaged cornea with a healthy one from a human donor, which is usually obtained from an eye bank. However, technological advances have allowed for the development of specialized procedures that replace only the damaged part of the cornea, while leaving the healthy parts intact.
Short for Descemet's stripping and automated endothelial keratoplasty, DSAEK replaces only the innermost layers of cells within the cornea, known as the endothelium. This allows the procedure to be performed through a much smaller incision with shorter recovery times and fewer risks than a traditional corneal transplant. DSAEK is commonly performed on patients with Fuchs' Dystrophy, an inherited eye disease that causes the cells of the endothelium to deteriorate, resulting in distorted vision and corneal swelling. As this condition progresses, vision will continue to worsen as damaged cells cannot grow back.
Short for Descemet's membrane endothelial keratoplasty, DMEK also replaces only the innermost layers of cells within the cornea, but uses extremely thin donor cornea tissue.