A cornea transplant is a procedure which replaces damaged tissue on the eye's clear surface. It can also be referred to as a corneal transplant, keratoplasty, penetrating keratoplasty (PK) or corneal graft.
Barnes-Jewish Hospital offers two types of corneal transplants - a deep anterior lamellar keratoplasty (DALK) and a Descemet's stripping endothelial keratoplasty (DSEK).
Deep Anterior Lamellar Keratoplasty
DALK, or deep anterior lamellar keratoplasty, is a partial-thickness corneal transplant that aims to preserves the two innermost layers of the host cornea: Descemet's membrane and the endothelium. The bulk of the diseased host cornea (such as scarring or thinning) will be removed and replaced by a healthy donor stroma (the bulk of corneal tissue). The host’s own endothelial layer is worth preserving if it is normal. The healthy endothelial layer keeps the cornea clear by removing fluid from the bulk of the cornea. Retaining this layer averts the risk of a potentially blinding graft rejection of the donor endothelial cells which may occur with conventional penetrating keratoplasty (full-thickness corneal transplant).
Descemet's Stripping Endothelial Keratoplasty
Descemet's stripping endothelial keratoplasty (DSEK) is a partial-thickness corneal transplant that aims to replace the diseased host endothelial cells while preserving the normal host stoma. This procedure involves replacing only the thin endothelial layer of the innermost cornea with donor endothelial tissue. Because it does not need to open the eye completely during the surgery, DSEK is a safer alternative to the conventional penetrating keratoplasty. The risk of graft rejection is potentially less than the conventional penetrating keratoplasty as the majority of the host cornea remains in place.
DSEK is a surgical option for patients who have damage to endothelial cells in the inner cornea due to glaucoma (optic nerve damage from high intraocular pressure) or cataract surgery or for those have hereditary Fuchs’ corneal dystrophy, in which the endothelial cells start to degenerate at much younger ages. Without healthy endothelial cells to pump water out of the eye, the fluid becomes retained in the corneal stroma and renders corneal cloudiness with a decreased vision. As DSEK does not require stitches to hold the donor tissue in place, it does not create additional astigmatism (irregular corneal curvatures) and thus has a faster vision recovery than the conventional penetrating keratoplasty.