The cornea is the outer layer at the front of the eye, it helps to focus light rays onto the retina. When it is damaged it can become less transparent or its shape can change, this can prevent light reaching the retina which, in turn, distorts vision.
A cornea transplant (or keratoplasty) is a type of eye surgery which replaces all or part of a diseased or damaged cornea with healthy tissue from an organ donor. The aim of the operation may be to improve sight, relieve pain or treat severe infection or damage. The operation is performed by an ophthalmologist.
Types of cornea transplant
There are three different types of cornea transplant, the one which is opted for depends on which part of the cornea is damaged or how much of it needs replacing:
- Penetrating keratoplasty (PK) - the entire cornea is replaced.
- Deep anterior lamellar keratoplasty (DALK) - the outer and middle layers are replaced or reshaped.
- Endothelial keratoplasty (EK) - the back layer is replaced.
A cornea transplant is a quick operation which usually takes less than an hour, patients either leave the hospital on the same day or on the following day. It can be carried out under general anaesthetic or local anaesthetic. If the outer cornea is replaced, it is held in place using stitches which, are taken out after around one year. If the back layer is replaced stitches are not needed, an air bubble holds it in place.
The cornea transplant recovery
If the entire cornea is replaced the recovery is slow. It takes arounds 18 months, though it’s usually possible to provide glasses or contact lenses much earlier. If just one of the layers needs replacing recovery time is much quicker, between a few weeks and a few months. During the recovery it is very important to take good care of your eye. Certain activities such as contact sports and swimming need to be avoided until your doctor tells you it is safe.
As with all surgical operations, there are risks. There are always risks associated with general anaesthetic and there is always the chance of infection. Around 95% of full replacements last at least ten years. There is a small risk that the new cornea is rejected by the body.