Defective corneas are the leading cause of reversible blindness worldwide and the second leading cause of blindness in the United States. Nearly 95 percent of those who have a defective cornea may receive help through a corneal transplant. Corneal transplantation, or penetrating keratoplasty (PKP), enables most patients who have suffered visual loss due to corneal opacity or deformity to see again. Today, corneal transplantation is one of the most successful transplant operations, largely due to modern eye banking methods.
Also, improved surgical techniques, effective medications, and a better understanding of the complex relationship between the eye and the transplant procedure have been attributed to an increase in the number of successful transplants.
Penetrating Keratoplsty or Corneal Transplant is the most commonly performed operation, and involves a full-thickness replacement of the central cornea. A circular disc of 7-8mm diameter is cut from the diseased eye and replaced by clear cornea removed in the same manner from the donor eye.
This is then sewn in place with very fine stitches which are removed about 12 to 18 months later. The operation takes about 1 hour.
Serious complications are uncommon following graft surgery. However, it is a major eye operation and like all operations may be accompanied by complications including haemorrhage (bleeding in the eye) and damage to other parts of the eye. The period after the operation can be complicated by infection, rejection, glaucoma, cataract and retinal detachment, as well as other, less common complications.
Therefore, it is essential that you keep your follow-up appointments, and seek prompt medical help should sudden or severe symptoms occur.
Eye drops are very important after the operation in preventing infection, inflammation and other complications. I may ask you to put in eye drops for 12 months or more after the operation.
Donor corneal grafts may be rejected by your body if your body recognises the foreign tissue and your immune system then tries to damage it. This is not an “all or nothing” condition, and provided it is diagnosed early enough it can usually be successfully treated. Please seek prompt medical advice if you experience one or more of the following:
Rejection can occur at ANY time after a corneal graft, even years later after your discharge from Outpatients. Rejections occur more often in the first year after the operation following a change of treatment, after removal of stitches, as a result of eye infection or injury.
Failure to obtain the correct treatment early can result in permanent loss of sight and the need for a repeat operation which carries a higher risk of failure than the first.
What are the chances of my graft being successful?
The success rate is good (e.g. ~90% of corneas grafted for keratoconus still clear 5 years after surgery) but it varies depending on the reason why you need a corneal graft and your general health.