Corneal Transplant – The Operation
Keratoplasty is a fairly simple though delicate surgery of the eye carried out under local or general anaesthesia depending on the age and condition of the patient.
First, a small circular knife known as the trephine is used to cut out the diseased or scarred portion of the patient’s eye. Then, good tissue of a corresponding size is removed from the cornea of the donor eye. This is sutured in the area of the eye from where the problematic tissue was removed using extremely fine sutures. The transplant surgery usually takes between 30 and 90 minutes.
For patients with a cataract (cloudy lens), the cataract may be replaced with a clear plastic lens during the transplant operation. If the patient has a faulty lens that is damaging the cornea, it may be removed and replaced with a new lens at this time.
Medication and Follow-Up
Following the graft, the surgeon will prescribe antibiotic and steroid eye drops to the patient which will have to be used meticulously. Though, initially, the drops will have to be applied many times in the course of the day, the frequency will be gradually reduced over the weeks. In some cases, low dosage steroid drops are continued indefinitely. The steroid eye drops, whatever the dose, have no side-effects whatsoever.
As there is always a risk of rejection, regular post-operative visits are imperative. Though sometimes pain and redness may accompany rejection – in this case, the patient must see his doctor immediately – there are times when there may be little or no visible symptoms.
Apart from redness, sensitivity to lights, loss of vision and pain, it is also important to report, without any delay, flashing lights, floaters, and loss of peripheral vision.
No patient can afford to be lax about his monthly hospital visits during the first six months post-surgery and at periodic intervals thereafter. Life-long yearly check-ups are usually prescribed.
Rejection occurs when the patient’s immune system attacks the grafted tissue on the assumption that the foreign cells are harmful to the body.
The cells that police the body attack the endothelium, the innermost cell layer of the donor cornea. One important function of the endothelium is to pump water out of the cornea to keep it clear. When the endothelium comes under attack, it is no longer able to function properly and consequently, the transplanted cornea becomes swollen and cloudy.
Chances of Rejection
Though the corneal transplant is the most successful of all organ transplants, there is still a 20 to 30 percent chance of rejection. However, rejection can be dealt with and treated if medication is administered at the first warning signs.
Some of the early symptoms of rejection, that should be looked into immediately, include decreased vision, increased redness and / or pain, and increased sensitivity to light. If any of these symptoms last for more than six hours, the patient stands a high risk of rejection.