Until recently, the only way to replace the endothelium was with a full thickness corneal transplant which required multiple sutures. A split thickness transplant is called endothelial keratoplasty. In this procedure, the back portion of the split donor cornea is used to replace only the diseased endothelial portion of your cornea, leaving the rest of your cornea intact. The device used to prepare the donor tissue is very similar to that used in LASIK. The formal term is Descemet's Stripping Endothelial Keratoplasty or DSEK. This type of surgery has been successfully performed on patients in the Netherlands since 2002 and in the United States for over 5 years.
Split-thickness corneal transplants have been done for many years to replace the front part of the cornea and they have been highly successful. This procedure is different because the surgical procedure involves replacement of the back layers of the cornea rather than the front layers. This replacement is done through a small pocket incision to avoid changes in the front surface of the cornea. An air bubble is used to hold the new layer against the back of the old cornea. After 36 hours or so the air is naturally absorbed leaving the two fused together. By leaving the front surface of the cornea without sutures or large incisions, the healing and recovery time for the patient is quicker, more comfortable and safer.
BENEFITS OF DSEK
1. Patients who have a DSEK have been shown to have a smoother corneal surface than patients that have a full-thickness standard corneal transplant. This happens because the natural surface of the cornea is not replaced so the focusing power of the cornea remains more natural and therefore more stable than with a full-thickness corneal transplant. It is expected that matching between the focusing power of your lens (or the artificial lens you received at the time of cataract surgery) and the focusing of the surface of your cornea is better. Therefore, there is less of a chance of you needing thick glasses after a split-thickness transplant when compared to a full-thickness corneal transplant.
2. Patients who have a standard full-thickness corneal transplant need either 16 sutures or one long looping suture, all of which cause more discomfort and more irregularity to the surface than has been shown with the split-thickness transplants.
3. If the endothelial cells that are transplanted by this split-thickness corneal transplant function normally as expected, then the cornea will lose its swelling and become clearer at a much faster rate than with a standard full-thickness corneal transplant.