A corneal transplant is surgery to remove all or part of a damaged cornea and replace it with healthy, clear cornea tissue from the eye of a donor who has died.
Usually a transplant is considered if your cornea is damaged or distorted to a point where the vision can no longer be improved with glasses or contact lenses and if any treatment you are having is no longer dealing with any pain or discomfort the corneal problem is causing you. Corneal transplants can also be used for corneal injuries.
Your ophthalmologist will discuss with you how a corneal transplant will help and they should help you make the decision on when to have your transplant.
There are three types of corneal transplant. The type of transplant you will be offered depends how the corneal problem you have is affecting your cornea.
DALK removes only the top layers from a very small area in the centre of your cornea, leaving behind the innermost "endothelial" layer. Your ophthalmologist then places a "button" of donor cornea containing these top layers onto your cornea. This button of donor tissue is held in place by tiny stitches until it heals in place. DALK usually takes about a year to heal. Some stitches may be removed before this, but usually not before the first six months.
EK replaces only the innermost layers of the cornea and is only suitable for dystrophies and conditions that affect the endothelial layer of the cornea. A bubble of air is used to hold the new endothelium onto the inside of your cornea.
EK transplants are quick to heal. Most people notice their vision getting better within the first week or two but it may take three months to get the full improvement.
PK is a "full thickness" transplant. This is where your whole cornea is replaced by a donor cornea, which is held in place with stitches.
PK is more likely to be offered if you have already had a DALK transplant, which has not worked, or if the stroma and endothelial (inner) layers of your cornea are damaged.
Stitches are not normally removed until a year after surgery. Your vision can improve while the transplant is healing, but it takes 18 months for a PK transplant to fully heal, and for you to see the full improvement in your vision.
Our full guide to corneal transplant covers the transplants mentioned above and includes more information about the surgery and recovery.