Corneal Transplantation

The cornea is the tissue on the very front of the eye. It is clear and covers the iris and pupil. It works with the lens to provide focusing power to the eye. If the cornea becomes opaque, swollen, or scarred, vision is compromised. Medication to control the damage to the cornea is usually the first line of treatment, but once it is clear that medication will not halt or alter the damage, a corneal transplant is considered. This surgical procedure involves the removal of the damaged tissue and replacement with a healthy, donated human cornea.

Because this procedure is a transplant of foreign tissue into the eye, rejection of the tissue by the immune system of the recipient is the greatest risk. However, drugs can be used to hold back the rejection reaction both before it occurs and even after the fact. Despite the availability of immunosuppressive drugs, the rejection rate for corneal transplants remains between 5 to 30% of the time.

What are the most common benefits of this surgery?
The transplanted tissue will enable the patient to regain much of the eyesight lost by the condition which damaged the patient's own cornea. The surgery can also eliminate symptoms due to the corneal condition. Because this procedure is performed only after medicines and other treatments have failed, it is the final method of providing relatively normal eyesight to someone having serious vision problems due to damage to their cornea.

What will happen at the initial consultation?
Once your ophthalmologist has determined you need a corneal transplant he or she will perform a full physical to determine whether you have any conditions or are taking any medications that might affect the surgery. He or she will then arrange for you to be put on the list of persons waiting for corneal transplant tissue. Usually the wait is short.

How is the procedure performed?
The transplant procedure involves removing the diseased or damaged tissue, then replacing it with the donor tissue. The entire operation is done under a surgical microscope. After taking measurements of the amount of tissue to be removed, the diseased corneal is cut and lifted away from the eye with a special round tool that works much like a cookie cutter called a trephine. Once the damaged tissue is removed, the donor cornea is cut to a matching size and placed on the patient's eye. It is held in place with very fine stitches using suture material that is about as thin as a hair.

In some cases where the primary problem is failure of the back layer of the cornea (the “endothelium”), this layer can be selectively replaces with a procedure called deep stromal automated endothelial keratoplasty (“DSAEK”). The benefits of DSAEK include faster recovery, fewer problems with astigmatism, and a lower risk of serious complications during surgery. One major drawback of DSAEK is that fewer patients achieve 20/20 vision after surgery than with traditional full thickness transplantation. DSAEK not an option for all patients and is a relatively new procedure, so you should discuss with your surgeon whether this procedure is an option for you.

If there is also a cataract present, this can be removed at the same time or later and replaced with an intraocular lens.

 

At the conclusion of the corneal transplant procedure, a patch and a metal shield are place over the eye to protect it.

How long does the surgery take?
The operation usually lasts between 1 and 2 hours.

Where will the procedure be performed?
The procedure is performed in an operating room of an outpatient surgery center or hospital.

How much pain is there?
The surgery is painless due to the administration of a local anesthetic at the beginning. Some patients may be given general anesthesia, particularly if their overall medical condition is in question. Most pain medicine should be able to control any residual pain present during the recovery period.

What can I expect after the procedure?
If the procedure is performed under local anesthesia, you can go home after a short stay in the recovery area. You will need someone to drive you home. The use of general anesthesia will delay your leaving by about two additional hours, to make sure the effects are wearing off.

After the procedure it is important to use the eye drops as prescribed, to not rub or press on the eye, to use over-the-counter pain medication, reduce exercise until healed, use the eye shields and patches as direct by your doctor, and not to drive until given approval.

What is the recovery period like?
The recovery period for corneal transplants is rather long. The stitches will remain in the eye for six to twelve months after the surgery. Eye drops will have to be used while the stitches are in place to assure proper healing and low doses of steroid eye drops are often prescribed on a permanent basis to prevent rejection.

An extremely important part of the recovery period is constant vigilance as to signs of rejection. Rejection occurs in 5-30% of all transplants and there is an increased risk if this operation is a second transplant after rejection of an initial one. If the rejection is noticed early, medication can be administered that will halt the reaction and save the transplant. Rejection occurs because the body's immune system recognizes the donor tissue as foreign and mounts a response against it. This damages the tissue such that it can no longer maintain the fluid balance, causing it to swell and lose clarity. Although the tissue will not fall out of the eye upon rejection, another transplant may be necessary to replace the tissue if too much damage occurs.

There are four signs of rejection that can be remembered by the mnemonic RSVP: redness, sensitivity to light, decreased vision, or pain. Any of these four symptoms, experienced after the initial healing period, should be reported to your ophthalmologist immediately.

What is the long-term outcome like for most people?
Vision will return slowly after the operation, with final improvements seen as far out as a year after it is performed. If there are no other conditions to complicate the recovery, the chances for greatly improved vision as compared to before the surgery are very good. Spectacles or contact lenses are usually necessary to correct astigmatism (irregular curvature) of the transplanted tissue, but these problems are minor compared to the vision issues present with the damaged cornea. The final result statistics are highly dependent on the cause of the damage to the original cornea -- with rates around 90-95% success treating corneal diseases such as keratoconus and corneal dystrophies and much lower rates for other problems such as viral infections, chemical burns or other inflammations of the eye.

However, even for persons suffering from chemical burns there is hope. A new technique has been developed that involves the transplantation of stem cells from a donor to grow a new surface over the removed damage cells. Then a standard transplant is done. This modification has greatly improved results for persons suffering from chemical damage.

The greatest threat to satisfactory long-term vision is rejection of the corneal transplant. Rejection is most common during the first year after the procedure but can occur at any time after the transplant, even years later. However, if a patient carefully watches for the signs of rejection, many reactions can be controlled with medication. In rare cases, the disease that affected the original tissue will reoccur in the transplanted cornea.

Ideal candidate:

Corneal damage from many different sources can be treated with a transplant. Some examples of conditions that can result in a transplant are

• corneal failure after other eye surgery

• keratoconus -- a disease involving abnormal curvature of the cornea

• inherited corneal diseases

• scarring after infections -- particularly herpes

• rejection of a first transplant

• scarring after a physical injury.

Whatever the source of the damage, an ideal candidate has explored pharmaceutical treatments to these problems and they have been eliminated in their case. The vision from the diseased cornea should be so affected as to justify the risks inherent in a transplant procedure.

Other important information:
Research is currently being conducted into an oral vaccine that appears to significantly reduce the amount of rejection of corneal transplants. Although this work was done in mice, it is being attempted in humans and might be something you would want to discuss with your ophthalmologist, particularly if this transplant is following up an earlier rejection.

Risks and Limitations:
The greatest risk with corneal transplants is rejection, although this can be treated with immunosuppressive medicine if caught in the early stages. Other risks that are much less prevalent but do occur are infection, bleeding, swelling or detachment of the retina, or glaucoma. Another type of problem that can happen with the transplant is an irregular curvature (astigmatism) that can slow the development of clear vision. This can be treated with Rigid contact lenses or, in some cases, further surgery.

Corneal transplants are most successful if the damaged cornea is the sole vision problem in the eye. If other damage is present, particularly if due to a continuing condition, such as diabetes, vision can remain compromised even after the transplant. However, if the vision quality is improved, it may make sense to undergo the transplant despite the knowledge that the resulting vision will not be perfect.

Cost:
The cost of surgery vary significantly among surgeons, medical facilities, and regions of the country. The fee will also vary depending on whether local or general anesthesia is used. Patients who are younger, sicker, or need more extensive surgery will require more intensive and expensive treatment.

Surgery charges for an outpatient procedure can be separated into five parts: 1) the surgeon's fee, 2) the anesthesiologist's fee, 3) the hospital charge for the operating room, 4) the medications, and 5) additional charges.

• Surgeon's fee: variable

• Anesthesiologist's fee: averages $350 to $400 per hour

• Hospital charges: variable

• Medication charges: $200 to $400

Additional charges: assisting surgeon, treatment of complications, diagnostic procedures (such as blood or X-ray exams), medical supplies, or equipment use.

Be sure to:

• Tell your doctor about any medical conditions you have and any medications that you are taking. Include any self-prescribed medications that your are taking, such as herbs or other natural remedies.

• Carefully follow the doctor's instructions regarding the use of eye drops and shields after the surgery.

• Arrange for someone to drive you home after the surgery.

• Be on constant lookout for rejection symptoms. Remember that this can occur even years after the surgery.

Dr. Talamo has advanced training in the treatment of corneal diseases such as dry eye, keratoconus, corneal dystrophies and problems arising after cataract surgery. He has been performing corneal transplant surgery for close to 20 years, and offers not only conventional transplant techniques but also new treatments such as selective endothelial transplantaion (DSAEK).  Dr. Talamo was the first surgeon in New England to use Intacs to treat keratoconus and performs this surgery routinely, frequently delaying the need for corneal transplant surgery.

Find Coneal Transplantation near Boston, Massachusetts. Call us at (781) 890-1023 to schedule a consultation with Talamo Laser Eye Consultants.