Before You Have a Corneal Transplant

An illustration of a corneal transplant. BSIP/UIG

Facing the fact that you need a corneal transplant may be difficult. A corneal transplant is major eye surgery and you are right to be concerned about it. However, with today’s technology, most people who undergo a corneal transplant experience a relatively uneventful process. Learning more about what is involved in a corneal transplant will put most of your concerns at ease.

What Is a Corneal Transplant?

The cornea is the clear, dome-like structure on the front part of the eye.

It acts like a camera lens, along with the natural crystalline lens of the eye, to help focus light onto the retina. Several conditions associated with the cornea can cause reduced vision including scarring, an abnormal shape, steepness, or excessive swelling. Vision can be so blurred or distorted that quality of life is reduced. Severe opacification or scarring of the cornea can even cause blindness. A corneal transplant involves replacing a damaged cornea with a healthy cornea in order to restore vision.

Common conditions that may warrant a corneal transplant include the following:

  • Keratoconus (a bulging or steepening of the cornea)
  • Fuch’s dystrophy (severe swelling caused by a loss of function of the cells on the back layer of the cornea)
  • Scarring after infection (bacteria, viruses or amoeba)
  • Scarring after an accident or trauma to the eye
  • Corneal failure after cataract surgery
  • Cornea rejection after an initial corneal transplant

    Types of Corneal Transplant

    There are two basic types of corneal transplant: a full-thickness transplant, called a PKP or penetrating keratoplasty, and a posterior or back-layer transplant, referred to as an EK procedure, or endothelial keratoplasty. Your eye surgeon will determine which type of corneal transplant is best for your particular condition.

    Before the surgery

    Before your corneal transplant, your doctor will put you on a list for the local eye bank. Once the tissue is obtained it will be tested for diseases such as HIV or hepatitis. The tissue will also be checked for clarity and quality. Your doctor will examine your eyes and conduct special tests to make sure your eye is ready for surgery. You will be asked to undergo routine laboratory tests such as a blood count and an EKG to make sure you are healthy enough to undergo surgery. You will be asked not to eat or drink after midnight before your surgery.

    During the surgery

    Either local or general anesthesia may be used in most cases. Your doctor will discuss with you what type of anesthesia is best for you. Once you enter the operating room, your eyelids will be cleansed and covered with a sterile drape. Oxygen will be given to you by a plastic tube placed near your nose. The surgeon will then place a microscope over your eye.

    During a full thickness, penetrating keratoplasty procedure, a circular instrument called a trephine is used to remove the center of the cornea.

    A button of donor corneal tissue is also cut to fit. The donor tissue is sewn into place with fine sutures.

    Alternatively, many surgeons are now using a femtosecond laser to cut a patient’s cornea and donor tissue. The laser allows the tissue to be cut in zig-zag patterns and at controlled depths for maximum precision. This allows the incision of the patient’s tissue and the donor cornea to fit together like a puzzle piece. With traditional transplants performed with a trephine, it could take from six to twelve months to stabilize and to obtained better vision. However, with the femtosecond laser, the precise incision heals faster, allowing more rapid suture removal and better vision.

    In the EK or endothelial keratoplasty procedure, only the back layer of the cornea is replaced. The patient tends to heal much faster with this procedure, as the entire cornea is not being replaced. After the procedure is complete, an eye shield will be applied to protect the eye. You will then be taken to a recovery room to rest before being discharged.

    After the surgery

    The eye is usually patched anywhere from 1 to 3 days. Your eye doctor will usually see you the very next day and remove the eye patch. He or she will examine the surgery to monitor healing and watch for rejection of the tissue. After the first or second day after surgery, you may return to normal activities such as brushing your teeth, bathing, bending over, reading, walking or watching TV. Using your eye will not hurt your eye or affect healing. You should avoid any rigorous sports or rough contact with the face or the eye. It may be recommended to continue wearing an eye shield for the first week or two after surgery just to protect your eye at night while you sleep.

    You must be very diligent about instilling your eye drops just as the doctor prescribes. One of the most important components of your post-operative care is to keep all your doctor’s appointments. Your doctor will need to know if the tissue begins to be rejected. One out of every four transplant recipients experiences a graft rejection. If caught early, however, it can usually be reversed with medication.

    Signs of corneal transplant rejection

    Keep the following acronym in mind after your surgery: RSVP.

    • R:  Redness - Sudden eye redness is a sign of rejection.
    • S:  Sensitivity - A rejection often causes significant light sensitivity.
    • V:  Vision - A rejection can cause blurry, foggy or cloudy vision.
    • P:  Pain - A sudden increase in eye pain or foreign body sensation can be a sign of a rejection.

    After a few months, the cornea will be stable enough to be measured for new eyeglasses. In some cases, astigmatism or nearsightedness may develop, but eyeglasses can easily correct the problem.  In other cases, a special contact lens may be needed to cover any distortion remaining on the cornea.

     Source:  Thompson RW, Price MO, Bowers PJ, Price FW. Long-term graft survival after penetrating keratoplasty. Ophthalmology, 2003; 121:1087-1092. 

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