The cornea contains five layers. Cornea transplants don't always transfer all the layers.
Types of cornea transplants include:
Penetrating (full thickness) cornea transplant. This involves transplanting all the layers of the cornea from the donor.
Lamellar cornea transplant. During this procedure, the surgeon only replaces some of the layers of the cornea with the transplant.
In a lamellar cornea transplant, selected layers are transplanted, which can include the deepest layer, called the endothelium (posterior lamellar cornea transplant). A commonly performed version of this procedure is the Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK). Or it can include layers closer to the surface (anterior lamellar cornea transplant).
Lamellar transplants may be more appropriate than full penetrating transplants when the disease process is limited to only a portion of the cornea.
You may need a cornea transplant if your cornea no longer lets light enter your eye properly because of scarring or disease.