Corneal endothelial dysfunction from disease or trauma is one of the leading indications for corneal transplantation. In the past, the only solution for endothelial replacement was through full thickness corneal transplantation. While the full-thickness corneal transplant, a.k.a., penetrating keratoplasty (PK), has been shown to replace the diseased corneal endothelium with healthy donor tissue, this procedure has been plagued by the inherent problems of unpredictable surface topography, retained surface sutures, and poor wound strength.
In 1998, Dr. Melles from the Netherlands described a new corneal endothelial transplant technique in the first human patients and called it posterior deep lamellar keratoplasty (DLEK). All of this work represents a radical departure from the conventional corneal transplant technique in that the DLEK surgery accomplished the goal of endothelial replacement without ever touching the surface of the recipient cornea. By eliminating surface corneal sutures and incisions, the advantages of normal corneal topography and faster wound healing were obtained, leading to faster visual rehabilitation and a more stable globe for the patient.
In recent years, a modification of the endothelial keratoplasty utilizing the stripping of Descemet’s membrane has been popularized as Descemets Stripping Endothelial Keratoplasty, or DSEK. The DSEK procedure has the advantage of providing a smoother interface on the recipient side for the visual axis. Preparation of the donor tissue in endothelial keratoplasty has also been made easier with the utilization of an automated microkeratome, and the addition of this component to the surgical procedure has been described as Descemets Stripping Automated Endothelial Keratoplasty, or DSAEK. Currently, we use a Moria microkeratome and artificial chamber system for the preparation of donor material for DSAEK. Dr. Huang, our corneal specialists at UMC is the first eye surgeons in the state of Mississippi to offer this procedure to our patients.
For further information, please contact UMC Ophthalmology at (601) 815-3248 (Dr. Huang).
Frequently Asked Questions (FAQ):
What type of anesthesia do you use for this procedure?
What medications do I use before the surgery?
What if I have cataract and corneal endothelial diseases?
How do you prepare the donor tissue for DSAEK?
How is DSAEK surgery performed?
What do I need to do immediately after surgery?
What would be the normal postoperative course?
What are the advantages of DSAEK versus conventional corneal transplant?
Links to DSAEK Surgery
What type of anesthesia do you use for this procedure?
DSAEK surgery could be done under retrobulbar block anesthesia, an injection of anesthetic medicine to the back of an eye. General anesthesia is often necessary since it minimizes posterior pressure on the globe and the risk of patient movement during the surgery.
What medications do I use before the surgery?
We typically use an eye drop (1% pilocarpine) to constrict the patient’s pupil right before the surgery. However, dilating drops will be used if combined procedures of DSAEK and cataract surgery are performed.
What if I have cataract and corneal endothelial diseases?
The cataract will have to be removed first with cataract surgery and intraocular lens implant, followed by DSAEK surgery. These two surgeries could be done simultaneously or with a staged approach.
How do you prepare the donor tissue for DSAEK?
The donor corneal tissue is prepared with a Moria microkeratome and an artificial chamber just prior to the surgery on the patient’s eye. The donor tissue is placed onto an artificial chamber and cut with a microkeratome to a depth of 300 or 350 microns and 9.5 mm or more in diameter. The cut donor tissue is then punched with a Hana trephine to 9 mm in size for the transplant.
How is DSAEK surgery performed?
DSAEK surgery is performed with a small incision from the temporal side of the cornea in order to provide the greatest manual access and visualization for the surgeon. Two clear corneal incisions are also placed about 5 clock hours apart to be used as access points to the anterior chamber during the operation. A reverse Sinskey hook is used for the descemets stripping portion of the procedure. The diseased endothelium and thickened descemets membrane of the recipient is punctured by the blunt tip of the reverse Sinskey hook. Once descemets membrane has been completely stripped with the hook, the diseased tissue can be removed from the chamber and sent to pathology.
The previously-prepared donor tissue is then folded with a pair of special folding forceps and implanted into the anterior chamber of the eye. After manipulations to center the donor tissue inside the eye and to remove the fluid between the donor tissue and the host, the anterior chamber is then completely filled with air to help with the adherence of the donor tissue to the endothelial side of the cornea.
What do I need to do immediately after surgery?
An occlusive patch and shield are routinely placed on your eye after the surgery. The patient is then discharged from the outpatient hospital when fully recovered from anesthesia. The patients are required to lie in a supine position, flat, facing the ceiling, for the first hour after surgery and then as much as reasonably possible to allow the retained air bubble to further stabilize the graft position.
What would be the normal postoperative course?
The patient is seen the next morning and the patch is removed. Most patients would not encounter any discomfort that would require any narcotic pain relief. If the donor tissue transplant is dislocated, then the patient will need to be taken back to surgery for the repositioning of donor tissue with more air bubbles.
If the graft is in good position on day one, it will heal in good position. The edges of the graft seal down with solid healing sometime within the first 3 months. The overlying cornea has a variable rate of clearing, but some patients are able to see as well as 20/25 only one week after DSEK surgery with a crystal clear central cornea.
The postoperative medical therapy after DSEK surgery is identical to what is done with conventional corneal transplant surgery patients. Topical steroids (1% prednisolone acetate) is used four times a day for 3 months, then three times a day until 6 months, then twice a day until 9 months, and then once a day until one year postoperatively. The steroids are then tapered down further until discontinued entirely. Topical antibiotic eye drops are used four times a day for the first two weeks after DSAEK surgery and then discontinued.
What are the advantages of DSAEK versus conventional corneal transplant?
DSEAK offers:
Faster visual rehabilitation
No corneal surface sutures
More stable ocular surface and globe
Less induced astigmatism
This week in UMC news report on Dr. Huang's DSAEK patients.
Focus on DSAEK Eye Surgery: WebMD report and video.