What is PKP?
Cornea transplant, also called Penetrating Keratoplasty (PKP), is a procedure which involves the replacement of the eye’s damaged cornea with a donor cornea. The need for a corneal transplant is usually due to disease, injury, infection, previous eye surgery, or other problems.
Immediately prior to surgery, you will be given local anesthesia to numb your eye and control unnecessary eye movement. In addition, you will also be given a sedative to relieve any anxiety you may be experiencing. Your surgeon will begin by removing a button of tissue from your cornea with micro-surgical instruments. A donor cornea will be prepared and a matching disc of the donor’s corneal tissue will be secured to your eye with delicate sutures. These sutures are barely visible and will not irritate your eye. Since PKP is a slow healing procedure, these sutures will remain in place while the wound heals.
Frequently Asked Questions
Why would I need a corneal transplant?
A transplant is necessary if your cornea has been damaged due to disease, injury, infection, previous eye surgery, or other problems. Three common problems that may be treated with a corneal transplant include:
- Keratoconus – Causes the cornea to change shape and actually protrude outward like a cone. This distorts the light as it enters the eye. Keratoconus usually affects young adults and its cause is unknown.
- Injured Cornea – Corneas may be injured by infection, chemicals, or sharp objects. When any of these occur, the eye instinctively creates scar tissue to heal the injury. This scar tissue inhibits the transmission of light. This means that images may be very faint or distorted, or you may only be able to see light and shadows.
- Previous Eye Surgery – In some cases, you may develop problems with your cornea if you have had a previous eye surgery. At times, this can cause your cornea to become cloudy and swollen, making images appear faint or washed-out. It is possible that you may also experience increased glare and develop painful blisters.
Where does the donor tissue come from?
Donor tissue is provided by an eye bank, which carefully screen the tissue. As stipulated by Federal regulations, eye banks are required to screen all tissue for AIDS, hepatitis and a variety of other diseases. Only healthy tissue may be used for transplant surgery.
What is the success rate for a corneal transplant?
In most common conditions, 95%.
What can I expect my vision to be immediately following surgery?
In the first few weeks following surgery, your vision will be blurred. Between two to three months after your surgery, your vision will improve enough that some of your sutures may be removed and glasses prescribed to further focus your vision. Full recovery of your vision will likely begin at approximately six months post-operatively.
What are the risks?
Your doctor’s office can discuss with you the risks and side-effects of the surgery, and what you may be able to expect from the procedure. However, the most important risk factor is the risk of rejection of the transplant. Though this type of rejection only effects a small percent of those individuals who receive corneal transplant, rejection cannot develop during the first two months after surgery. Rejection can actually take place years later. Symptoms of rejection include redness, sensitivity, sudden change in vision, and pain. If any of these occur, contact your surgeon immediately. Often times, if rejection is caught soon enough, drops are successful at reversing the rejection and stabilizing the cornea. If rejection is not caught in time, a second corneal transplant may be performed, which also has a high success rate.