Cornea Endothelial Transplant
Corneal Endothelial Transplantation
It is considered to be a relatively new technique, which has led to a revolution in corneal transplants, because the results in terms of recovery speed and quality of vision are very satisfying. This technique is suitable for patients suffering from chronic edema of the cornea (bullous keratopathy) or from Fuch's endothelial dystrophy. Vesicular keratopathy usually occurs after cataract surgery or other operations.
On the posterior surface of the cornea, lies the Descemet membrane, which is in contact with the aqueous fluid. The membrane is covered by a layer of cells called endothelial. These cells have a pump mechanism to regulate the quantity of water in the cornea. Their number varies between patients. These cells tend to reduce over the years. Further reduction of the number of cells, either after surgery or as a consequence of a dystrophy (hereditary corneal disease) has as a result increased water proportions in the cornea. Initially the thickness of the cornea increases and later the cornea loses its translucency. Hence patients with damaged endothelium see blurry. Often eyesight is worse in the morning and is improved during the afternoon. This happens because during the day the corneal edema is reduced as evaporation of tears takes place.
Until recently, penetrating keratoplasty was performed to patients with this problem. Today, the appropriate treatment is the DSAEK (Descemet Stripping Automated Endothelial Keratoplasty) technique. In DSAEK, the surgeon first removes the Descemet membrane from the eye of the patient with the malfunctioning endothelium. Then the surgeon places in the affected eye, an 8.5 mm diameter disc (posterior lamellar transplantation) of posterior layer and a Descemet membrane with new healthy endothelium. This disc is made by the surgeon in the laboratory, with a special microkeratome, or the eye bank technicians manufacture it and send it to the surgeon (precut tissue for DSAEK). The graft comes from a deceased donor as in full thickness corneal transplantation.
The entrance of the endothelium in the affected eye is done through a small incision that is soon healed and as a result restoration of vision is quick and postoperative astigmatism is insignificant. Supportive stitches for the implant are not placed, and the graft stays in place with the aid of an air bubble. Stitches are placed in the main and the auxiliary incisions so that the air remains inside the anterior chamber until the graft consolidates. The air is absorbed on its own within one to two days.