Innovative Corneal Transplantation: DSEK or DMEK
A cornea transplant is a surgical procedure to replace part of your cornea with healthy corneal tissue to help improve your vision. Your cornea is the transparent, dome-shaped surface of your eye that accounts for a large part of your eye's focusing power. The human cornea is composed of three main 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 cornea can also suffer damage from trauma, infections, and conditions which change its shape and clarity.
A corneal transplant can restore vision, reduce pain and improve the appearance of a damaged or diseased cornea.
What is DSEK or DMEK?
Endothelial keratoplathy in the form of descemet’s stripping endothelial keratoplasty (DSEK) or descemet’s membrane endothelial keratoplasty (DMEK) is an advanced form of corneal transplantation in which the diseased or damaged endothelial cell lining is replaced with a new endothelial lining harvested from a donor cornea. This allows for a customized approach to treating the corneal condition without disrupting the healthy layers of the cornea.
DSEK and DMEK are outpatient procedures that do not require hospitalization. A thin button of healthy donor tissue containing only the endothelial cell layer is position onto the back surface of the patient’s cornea. DMEK is the latest and most advanced approach in which a pure exchange is performed and not added tissue is transplanted along with the needed healthy donor endothelial cells. DMEK offers further benefits to DSEK in that the visual outcome is better, the visual recovery is faster and the rejection rate is 10 fold less. These new techniques offera significant improvement over the standard operation of a full thickness corneal transplant. Dr. Shamie and Dr. Fram have had over a decade of experience in these advanced surgical techniques and can offer you the high level of skill and expertise required for the best outcome you can expect. The surgery is performed under local anesthesia, through a small incision with a reasonably short recovery.
Who are candidates for DSEK or DMEK?
Patient’s with symptomatic swelling in the cornea caused by damage to the inner endothelial lining of the cornea. 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.
What is the difference between DSEK/DMEK and a conventional corneal transplant?
DSEK and DMEK replace only the endothelial lining of the cornea, while the rest of the cornea is undisturbed. The new donated endothelial lining is held in place with an air bubble in the first 2-4 days without corneal sutures.
A conventional corneal transplant replaces the entire thickness of the cornea with a donated cornea and is held in place by up to 16 corneal sutures.
Corneal Transplantation: Traditional Penetrating Keratoplasty
Femtosecond Laser Corneal Transplantation:
Femtosecond laser keratoplasty is a corneal transplantation or grafting technique using a femtosecond laser to create the incision in a much more precise way than the traditional technique. This laser is capable of pulsing more than 60,000 times per second to create a zigzag incision which then allows for a better wound construction. This new technique results in a faster recovery and less astigmatism compared to conventional corneal transplantation methods. We have extensive experience in this form of corneal transplantation and will gladly offer it as the best option for you if your corneal condition is amenable to this type of surgical treatment.
Deep Anterior Lamellar Keratoplasty (DALK)
Deep Anterior Lamellar Keratoplasty is a special type of corneal transplant in which only the front part of the cornea is transplanted. The healthy back layer of your cornea is left untouched and intact allowing for a safer surgery with a better outcome. DALK allows for less chances of corneal rejection and a faster vision recovery. At Advanced Vision Care, we combine the benefits of the femtosecond laser and the DALK technique to allow a customized partial layer corneal transplant with the added benefits of the laser. If you suffer from keratoconus, corneal scarring, or any other conditions which similarly involve only the front layers of your cornea, this option may be the best option for you.
Traditional Corneal Transplant
Traditional 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. This surgery was first developed one hundred years ago, and the wonderful 90% success rate reported today is based on numerous refinements to this same basic technique. It has certainly stood the test of time.
The advantage of the traditional corneal transplant operation is the long and successful track record that we have with it. There is a 90% success rate. The rate of rejection is only about 8%. It is relatively easy to combine other surgery with it such as cataract extraction or glaucoma surgery. The disadvantages of the traditional corneal transplant operation are the time involved in performing the actual operation (45 to 60 minutes), the difficulties in suturing the new cornea in place, and occasional problems with the sutures which can come loose, cause infections, or cause astigmatism (an irregular corneal shape) . The astigmatism after traditional corneal transplant surgery can be so significant that eyeglasses alone won’t give adequate vision and some patients ultimately require contact lenses or additional surgery to reduce or eliminate the astigmatism. Because the wound is a full 360 degrees, and the sutures used are finer than human hair, the corneal transplant wound is always very delicate and at risk to rupture or break open from mild or incidental trauma, even several years after the surgery. The visual recovery can take 6 to 12 months.
Transplantation involves replacing the damaged cornea with a healthy one from a donor (usually through an eye bank). Keratoplasty is a low-risk procedure - it is the most common type of transplant surgery and has the highest success rate.
During the procedure, a circular incision is made in the cornea. A disc of tissue is removed and replaced with healthy tissue; these discs may be thin (lamellar keratoplasty) or as deep as the entire cornea (penetrating keratoplasty, the technique used in almost all corneal transplants). Local or general anesthesia may be used.
Dr. Fram and Dr. Shamie have extensive expertise in performing all the different variations of advanced corneal transplantation and customize the treatment to your specific corneal condition. Their effort and priority is in offering you the best vision possible with the fastest recovery. If you have further questions as to what options are best for you, please do not hesitate to schedule an appointment for consultation.
If you would like more information about Corneal Surgery or to schedule an appointment, feel free to fill out our convenient contact form or call us directly at 310.229.1220.