When a cornea becomes swollen, scarred and warped, light cannot pass through the cornea to reach the retina and then vision becomes decreased or lost depending on the severity of the corneal opacity. There are a number of diseases that can lead to a cloudy, swollen or warped cornea. These include, Fuchs' corneal dystrophy, keratoconus, corneal swelling after eye surgery, or scarring after corneal trauma. In these situations a full replacement of the cornea may be needed to restore or improve vision. The procedure is called Penetrating Keratoplasty (PK) or Corneal Transplant. During the procedure the almost the entire cornea is removed from the eye and replaced with a donor cornea. The donor tissue is secured with sutures that are placed on the edges of the transplant. The sutures will remain in place for several months and are slowly removed over the course of 1 to 2 years or it may be left in place indefinitely. Following surgery, eye medications are used to help prevent possible infections and graft rejection.
What is Corneal transplant Surgery?
The cornea is the tissue in 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%.
What are the most common benefits of this surgery?
The transplanted tissue will enable the patient to regain much of the eyesight that was 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?
Dr. John will first ask you questions about your eyes and your eyesight and how it is affecting your life-style and your daily activities. Then he will do a complete dilated eye examination to determine what is causing the decreased vision. Once it is determined that it is the corneal clouding or scarring that is causing the blurred vision and that medications cannot clear the cornea then he will inform you that surgery may be the next best option to improve your eye-sight. This is again an elective procedure in most cases, except when there is eye pain secondary to the corneal disease process. It will be your decision as to whether or not to have corneal transplant surgery. He will also tell you of the potential risks and complications of the surgery. It is an outpatient surgery, meaning you go hoime the same day. Once you state that you want to have the corneal transplant surgery, Dr. John and staff will give you a surgery date, and arrange for any additional tests that may be required depending the state of your eye. Then you will be asked to see a medical doctor before surgery to clear you for the surgery from a medical standpoint. Also, pre-operative tests will be arranged to be completed before the day of your eye surgery.
How is the procedure performed?
The traditional corneal transplant surgery involves removing the diseased or damaged tissue from you reye and replacing it with the healthy donor tissue. The entire operation is done under a surgical microscope. You will be asleep during the procedure and therefore will not feel any pain.
Most of the diseased cornea is removed surgically after using a circular blade (trephine) to cut into the cornea. This is then removed by using corneal micro-scissors. A similar procedure is performed on the donor cornea and the donor disc which is similar in size to the cornea that was removed is used to replace the patient's cornea with healthy donor tissue. The donor cornea is held in place with very fine stitches using suture material that is usually thinner than the human hair.
The newer corneal transplant procedures only replace the diseased part of the cornea with a similar healthy layer of donor corneal tissue. These procedures are together known as lamellar keratoplasty. Dr. John is considered to be one of the world leaders in lamellar keratoplasty surgery and has 3 surgical text-books on lamellar keratoplasty. When the primary problem is failure of the back layer of the cornea (the "endothelium"), this layer can be selectively replaced with a healthy layer of cells, known as Descemt's stripping automated endothelial keratoplasty ("DSAEK"). The benefits of DSAEK include faster recovery, fewer problems with astigmatism, and a lower risk of serious complications during surgery. DSAEK is 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 implant. At the conclusion of the corneal transplant procedure, a patch and a metal shield are place over the eye to protect it. Dr. John teaches the DSAEK surgery technique to corneal specialists in various parts of the United States and outside the country.
How long does the surgery take?
The operation itself will usually last about 20 to 30 minutes for DSAEK surgery and about 40 to 45 minutes for conventional corneal transplant surgery. There is additional time needed in the operating room in terms of setting up the instruments, anesthesia work, and prepping the eye before surgery
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 anesthesia. Anesthesia may be general anesthesia for the traditional type of surgery, and local anesthesia with sedation for DSAEK surgery which is the new, no-stitch corneal transplant surgery. During the immediate recovery period if you have pain you may take medication to control the pain. However, usually there is no pain after corneal transplant surgery whether it is the conventional or the new type of corneal transplant surgery.
What can I expect after the procedure?
After surgery, you can go home the same day. You will have a patch over the operated eye which comes off the next day when you go to see Dr. John for the check-up. You will be instructed to use your glasses during the day and an eye patch at night for 6 weeks following surgery so that you don't rub your eye against the pillow during sleep. After the procedure it is important to use the eye drops as prescribed, not to rub or press on the eye. There is usually no pain after surgery. However, if you need you can use over-the-counter pain medications as needed. You should not drive until your doctor approves it.
Restrictions after surgery lasts for 6 weeks and they include no lifting heavy objects (more than 10 pounds), no bending over and no straining. Other than that, you can do your regular activities. You should not work on any machinery since you may not have depth perception. Often the surgeon may wait for 1 year after surgery to prescribe glasses or contact lenses. Dr. John does this usually at an earlier date. After about 3 to 6 months following a conventional corneal transplant surgery DR. John usually will approve for you to get glasses or contact lenses to improve your vision. Dr. John also usually adjusts the sutures in a conventional corneal transplant surgery to get the best corneal shape after surgery that will help in getting the best uncorrected and corrected vision after surgery.
What is the recovery period like?
The recovery period for corneal transplants is rather long. The stitches will remain in the eye for twelve months or longer after the surgery. Eye drops will have to be used to assure proper healing and low doses of steroid eye drops are often prescribed on a permanent basis to help prevent graft rejection. Dr. John adjusts the sutures to get the best corneal shape during surgery and the sutures may be left indefinitely. These are not like skin sutures where they have to come out. These sutures are thinner rthan the human hair and you will usually not feel it. The only time when you usually feel the sutures is when they become loose or if they break. In either instance Dr. John will selectively remove those sutures in the office and this is a painless procedure.
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 conventional corneal transplant surgery, 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 cells 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 re-occur in the transplanted cornea. If you are not a candidate for corneal transplant then Dr. John will consider an artificial cornea that is made of plastic.
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 simplex virus
- 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.
Risks and Limitations:
The greatest risk with corneal transplants is rejection, although this can be treated with immunosuppressive medicine, namely eye drops, and if caught in the early stages it can often be reversed. 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 do occur after a corneal 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 due to other underlying causes especially in the back of the eye such as the retina.
The cost of surgery vary significantly among surgeons, medical facilities, and regions of the country. 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) any additional charges.
- Surgeon's fee: variable
- Anesthesiologist's fee: averages $350 to $400 per hour
- Hospital charges: variable
- Medication charges: may be $200 to $400
- Additional charges: diagnostic procedures (such as blood or X-ray exams), medical supplies, or equipment use.
Corneal transplant surgery is not cosmetic surgery, and as such, most insurance companies will cover the above fees. The amount or the percentage of insurance coverage will vary depending on your insurance company and you may wish to contact the insurance company directly. For Medicare patients, Dr. John accepts Medicare assaignment. Medicare will usually pay 80% of the Medicare approved fees. The remaining 20% you will be responsible for. If you have secondary insurance like Blue Cross Blue Shield or any other supplemental insurance, then the remaining 20% will be billed to that insurance company, and only what is left unpaid you will be responsible for to pay for the procedure.
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. If you are using any blood thinners like Coumadin, asprin, etc., you need to stop those before surgery to prevent excessive bleeding during surgery. However, you should not stop the medication by yourself. You need to tell your medical doctor about the surgery and he will instruct you as to what to do with regard to preparing for the corneal trasplant suregry. 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 and bring you to Dr. John's office the day after surgery for check-up. Be on the lookout for rejection symptoms. Remember that this can occur even years after the surgery, but most of the time it can be reversed with eye drops prescribed by your eye doctor.
The above information is provided by Thomas John Vision Institute, P.C., and is not intended to replace the medical service and advice of Dr. John. Kindly consult your health care provider for advice regarding a special medical/ocular condition.
Last Revised/Updated on April 25, 2009.