Partial thickness corneal transplant is quickly becoming the preferred method of corneal transplant surgery for those patients whose disease or injury is confined to specific layers of the cornea.
The cornea is made up of five layers, and disease can strike any one of these layers. When the entire cornea is affected, surgeons must perform a penetrating keratoplasty (PK), or a full thickness cornea transplant, to restore vision. But often times, disease may only be present in one or two layers of the cornea, leaving the remaining layers healthy and functional. In the past, PK surgery was the only solution, but today, advances in corneal transplant procedures now allow surgeons to remove and replace just the damaged or diseased corneal tissue rather than the entire cornea. This is known as a partial thickness cornea transplant.
There are two primary partial thickness corneal transplant procedures: DSAEK, descemet stripping with automated endothelial keratoplasty, and DALK, deep anterior lamellar keratoplasty.
In DSAEK surgery, only the two innermost layers of the cornea, the Descemet's membrane and the endothelium, are removed and replaced with a donor cornea.
During surgery, doctors gently strip off the diseased or injured cell layer lining the innermost part of the cornea. A microkeratome is then used to thinly slice a donor cornea and match it to the tissue removed. Next, the new corneal tissue is folded in half and inserted into a small incision. An air bubble is use to secure the tissue in place.
DSAEK has proven particularly useful in treating patients with Fuchs' corneal dystrophy and offers several advantages over traditional PK surgery, including:
- DSAEK is a less invasive procedure, replacing only the damaged cell layer rather than the entire thickness of the cornea.
- A smaller incision is used in DSAEK, leaving the eye structurally stronger post-operatively.
- Because fewer sutures are used in DSAEK, the risk for post-operative corneal astigmatism is reduced.
- In general, DSAEK patients experience a much faster healing time and better visual recovery, usually within 1-3 months.
DSAEK is generally performed on an outpatient basis using a local anesthetic. The procedure takes about 45 minutes to complete. The risks associated with DSAEK surgery are similar to traditional PK surgery and include possible graft displacement, graft rejection, hemorrhage, swelling and infection.
Talk with your doctor to learn more and see if you are a candidate for the DSAEK partial thickness corneal transplant procedure.