DSEK stands for Descemet’s Stripping Endothelial Keratoplasty and refers to a thin corneal layer called Descemet’s Membrane, named for an eighteenth century French doctor. This surgery is a corneal transplant or graft of this one layer, rather than of the full corneal thickness, as is done in a standard corneal transplant. Please see Eye Anatomy: The Cornea for more information.
There are three main corneal layers:
In addition to these layers, there are two very thin layers, one on each side of the stroma. Bowman’s layer is a tough, protective layer of collagen over the stroma. Descemet’s membrane is beneath the stroma and is called a basement membrane. It connects the stromal cells with the endothelial cells.
Since the endothelium pumps excess aqueous fluid out of the cornea which would otherwise cause swelling and cloudy vision, it is an important layer for clear vision. Descemet’s membrane helps to protect the endothelium.
Aqueous fluid provides nutrients to the cornea which has no blood vessels. They would obstruct vision. Oxygen is received by the corneal epithelium from the air.
Fuchs’ Dystrophy is an inherited corneal disease where the endothelium becomes less able to control the cornea’s fluid content. Little collagen bumps called guttata develop in place of endothelial cells. As you grow older, they grow in size and number and this causes nearby endothelial cells to die off.
The endothelium is only one cell thick and these cells cannot replace themselves. By midlife, there are too few to keep the cornea dry enough for clear vision. At this time, usually about age 50 or 60, the cornea has become swollen with excess aqueous fluid, and corneal transplant surgery may be considered.
DSEK is a newer procedure than a standard corneal transplant. Rather than replacing the full thickness of the cornea, it replaces just the endothelial cells and Descemet’s membrane. The rest of the cornea is still healthy and is left intact.
DSEK is also known as DSEAK for Descemet’s Stripping Endothelial Automated Keratoplasty. New technology has automated the preparation of the donor cornea.