DSAEK

Occasionally, either through disease or injury, the cornea isdamaged to a point where light can no longer effectively pass through it, resulting in reduced vision. When indicated by an ophthalmologist, a corneal transplant procedure may be performed which replaces the damaged cornea with a clear donor cornea.

WHAT IS DSAEK?

DSAEK (Descemet’s Stripping Automated Endothelial Keratoplasty) is a corneal transplant technique where the unhealthy, diseased, posterior portion of a patient’s cornea is removed and replaced with healthy donor tissue. Unlike conventional corneal transplant surgery known as penetrating keratoplasty (PKP), the DSAEK procedure utilizes a much smaller surgical incision and requires no corneal sutures. Patients enjoy more rapid visual recovery with the DSAEK in comparison to PRK.

INDICATIONS CORNEAL TRANSPLANT SURGERY UTILIZING THE DSAEK TECHNIQUE:

The human cornea is composed of multiple 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.
 
ADVANTAGES AND DISADVANTAGES OF DSAEK TECHNIQUE

There are several significant advantages to the DSAEK operation compared to the standard corneal transplant operation.  The operation is faster than traditional corneal transplantation.  The wound is smaller and closer in size and location to a cataract surgery incision.  The smaller wound is more stable and less likely to break open from inadvertent trauma.  Because the wound is smaller and requires far fewer sutures, there is very little postoperative astigmatism which can delay the visual recovery.  The maximum return in vision takes only about 3 to 4 months following DSAEK.  Since only the thin inner layer of the cornea is replaced, over 90% of the patient’s own cornea remains behind contributing to greater structural integrity and a reduced incidence of rejection.

POST-OPERATIVE CARE
 
Patients should understand the importance of the post-operative period.  During the surgery, an air bubble will be placed in the eye to assist with the adherence of the transplant to the host cornea.  For this reason, for the first 48 hours after surgery while the air bubble is still present in the eye, patients will be required to lay supine (flat on their back) to assist with graft adherence.  It is also crucial that patients to do not rub or touch their eye, as eye rubbing or touching the eye could cause transplant dislocation.  If the transplant does become dislocated, rebubbling and repositioning of the transplant will be required, either in the office or in the operating room.
 
DSAEK is not for everyone.  Some patients with corneal scarring or other conditions are not suitable candidates for DSAEK.  There are risks involved with the DSAEK operation.  Since corneal specialists have only been performing DSAEK for the past 2 to 3 years, there is no long-term follow-up.   There is a risk of the thin button of endothelium becoming displaced within the first few days or weeks after surgery and requiring a return trip to the operating room to reposition it.  If the DSAEK operation fails, the operation can be repeated with another button of donor endothelium.  If the DSAEK fails, either after one or multiple attempts, a traditional corneal transplant operation can be performed.