Descemet Stripping Endothelial Keratoplasty (DSEK) & Descemet membrane endothelial keratoplasty (DMEK)
Discover your options for corneal transplant surgery in Santa Rosa by learning about our DSEK and DMEK operations. To begin, the cornea is comprised of five basic layers of tissue. During a traditional corneal transplant, known as a "penetrating keratoplasty" or "PKP", a circular disc of the full thickness of the cornea (all five layers) is removed from the center of the cornea and replaced with healthy donor tissue. This new tissue is sutured in place. A full-thickness corneal transplant has been a safe and effective procedure for the treatment of damaged corneas for decades. Call us today for a consultation at (707) 546-9800.
What are the Benefits of DSEK & DMEK Versus PKP?
Dr. Ni has been performing DSEK corneal transplants for patients with persistent corneal swelling and poor vision. Dr. Ni has also been routinely performing DMEK procedures, the newest generation and most technically challenging type of partial-thickness transplants. These revolutionary procedures have nearly replaced the traditional corneal transplant. With a DSEK procedure, a thin sliver of healthy donor corneal tissue around 100 microns, consisting of a small portion of stroma, Descemet's membrane, and a layer of endothelial cells is used to replace the diseased back layer of the native cornea. In DMEK, replacement tissue is closest to the cornea's original anatomic condition, as it consists of a single layer of endothelial cells plus a 15-micron thin membrane. The advantages of the DSEK / DMEK methods of just transplanting the posterior part of the cornea are numerous:
- A much safer procedure than a full-thickness corneal transplant. During a DSEK or DMEK procedure, only two small incisions need to be made to allow the microsurgical instruments to strip off the diseased endothelium from the central portion of the patients’ cornea. After the donor corneal tissue layer is prepared, it is gently folded and placed within the fluid-filled anterior chamber of the eye, beneath the patient’s cornea. Injected sterile air creates an air bubble, which causes the donor tissue to unfold and holds it in the exact location where the original tissue was removed. This is a shorter procedure, usually requiring less than half the time it takes to undergo a traditional penetrating keratoplasty. The small incision, the need for fewer or no sutures, and the shorter procedure time make the DSEK and DMEK procedures extremely safe and produce amazing visual results.
- Stronger cornea after surgery. Since only the posterior layer has been replaced, minor trauma to the eye is less likely to cause a graft dislocation.
- Much more predictable refraction. Usually, one suture is used in a DSEK procedure and no sutures in a DMEK procedure. This means smaller changes in astigmatism, nearsightedness or farsightedness after the surgery. Another benefit of using fewer sutures is that the incidence of infection or irritation from them should be greatly reduced. The eye’s refractive status is dependent on the front shape and steepness of the cornea. In the DSEK/DMEK transplant method, the front surface remains unchanged, leaving better ocular balance between the eyes.
- Quicker visual recovery. Compared to the long recovery from a standard full-thickness corneal transplant, which can take up to one or two years, full visual recovery from a DSEK procedure can be as short as three months. This is due to the thinner tissue, smaller incision size, and the fact that fewer sutures are used. After DMEK procedures, patients can typically achieve driving vision within a week, with further improvement over the subsequent 1-2 months. Achieving 20/20 or 20/25 vision is also more common after DMEK than DSEK. Your surgeon will decide along with you whether you are a candidate for the latest DMEK technique.
Commonly Asked Questions
A DSEK procedure is done with the patient under local anesthesia. The procedure takes just 45 minutes, about half the time needed for a traditional cornea transplant.
After your surgery, you will have a patch over your eye. You will rest for the remainder of the day. For as much of this time as is possible, you’ll need to lie flat on your back looking directly upward. This position keeps the air bubble against the corneal transplant. The procedure requires only a tiny incision that requires just a single suture (often not even a single suture is required). You will receive several drops to prevent infection and to help the eye heal comfortably.
After just 48 hours there will only be limited restrictions to your activities. You’ll need to refrain from bending below the waist for three weeks following your surgery. Heavy lifting needs to wait three weeks, as well. You can usually drive within one week.
Your vision will be much better within one week, with 80 percent of your healing complete in one month. The remaining improvement will come over the next four to six months.
Your vision will be blurry after surgery due to swelling and the air bubble used to keep the transplant in place. The air bubble will be absorbed sometime within the first week, but swelling may persist for a month or two. As the swelling decreases, your vision will continue to improve. You may need new glasses while your eye is healing, but your vision will continue to improve. Patients without other eye problems usually achieve vision of 20/30 or better within a couple of months.
You will use anti-rejection eye drops for a number of years after your DSEK procedure. The risk of rejection with DSEK is around 12 percent, compared to a 20 percent risk with full-thickness corneal transplants.
The DSEK or DMEK corneal transplant is not a full-thickness transplant procedure. The minor surgery requires just a couple of very small incisions. These are made using microinstruments after our eye has been numbed using medicated eye drops. During the procedure, you will not feel any pain. Your doctor will carefully remove the diseased endothelium, the lining of the cornea, from the affected eye. Donor corneal tissue is inserted into place beneath the cornea, followed by the insertion of an air bubble. The air bubble helps to situate the donor tissue and also to hold it in place until it integrates with the surrounding tissue.
The fact that the DSEK procedure is more conservative than full-thickness corneal transplant surgery may give the impression that this approach is ideal in every situation. That's not the case. The DSEK or DMEK treatment process is suited to specific cases in which damage is localized to the inner layer of the cornea. Your experienced doctor will perform a comprehensive examination of all aspects of your eye to devise the treatment protocol that will be most appropriate for you.
After your consultation with an eye specialist, you can expect to receive written instructions and clear direction to help you plan for your surgery and recovery. For example, you will need to have someone drive you to your outpatient procedure and see you home afterward. Due to the necessity of an air bubble in your eye after surgery, you can benefit from planning ahead with pre-cooked meals, especially those that will not require you to look down at a dish. Finger foods are ideal in this situation. Depending on your medical history, your eye doctor may also require pre-surgical appointments and screenings to confirm your cardiac and pulmonary health and readiness for surgery.
Prior to having the DSEK procedure, you must review your current medications with your doctor. It may be necessary to adjust dosages or stop using certain medications that can thin your blood. If any of your blood-thinning medication is prescribed, it will be necessary to discuss alternatives with the prescribing doctor to adequately prepare for surgery.
Generally, DSEK and DMEK corneal surgery is considered less invasive than full-thickness corneal transplant procedures. The recovery from these minimally-invasive techniques is significantly shortened compared to full-thickness surgery. The structure of the eye is also preserved through the technique that focuses solely on the endothelial lining. Because the cornea is left intact, there is much less of a risk of complications such as refractive errors. That said, your doctor will discuss risks such as the potential dislocation of the graft during the recovery period. In some cases, it is necessary to progress treatment to a full-thickness corneal transplant.
Recovery from the DSEK or DMEK procedure is shorter and less involved than full-thickness corneal transplant surgery. Your doctor will discuss with you the side effects that you can expect after your procedure. For example, your vision may not clear for a week or longer after your procedure. This is because it is difficult to see through the air bubble that has been placed to hold your new corneal lining in place. As the bubble moves, you might see its shadow or curvature. You may also see the presence of the bubble when you look in a mirror. As the air bubble moves to the surface, vision will improve. Until that time, you may feel some aching, grittiness, irritation, or itching. During your recovery, it is important to avoid rubbing and touching your eye.