Descemets Stripping Endothelial Keratoplasty

The human cornea is composed of three layers, the outer or epithelial layer, the middle or stromal layer (which comprises about 90% of the total corneal thickness), and the inner or endothelial layer. The endothelial layer is composed of a single layer of thousands of small pump cells. These endothelial pump cells are responsible for pumping fluid out of the cornea so it can remain clear and thin and provide good vision for the eye. If the pump cells should become dysfunctional, damaged, or destroyed, the corneal fills up with fluid and becomes swollen and cloudy, and causes blurry vision.

The endothelial cells can be lost due to aging, from inherited diseases (such as Fuchs’ Corneal Dystrophy), from trauma, or from previous intraocular surgery. If a critical number of endothelial cells are lost, and the cornea becomes swollen and cloudy, medical therapy is usually not helpful and a corneal transplant operation is indicated. The remainder of the corneal layers, the stroma and the outer epithelium, are usually healthy. A large number of patients requiring corneal transplant surgery have these sorts of problems where only the endothelial cells have been or injured or lost.

Standard corneal transplant surgery has consisted of removing the entire cloudy cornea and replacing it with a full thickness donor cornea, thereby replacing all three layers of the cornea.
Ophthalmic researchers and surgeons have long recognized that for many patients needing a corneal transplant, only the diseased or missing endothelial cells needed to be replaced, as the stroma and epithelial layers were otherwise normal. Recently, a new technique called DSEK has evolved in corneal transplant surgery which accomplishes the goal of replacing only the endothelial cell layer. A thin button of donor tissue containing only the endothelial cell layer is inserted onto the back surface of the patient’s cornea. This new technique appears to be a significant improvement over the standard operation. The surgical skill and expertise required is the same, but the surgery itself takes less time with an experienced surgeon, involves a smaller surgical incision, requires far fewer sutures, heals faster and more reliably, and the vision returns faster.