Tests and treatments
What is it?
The most important function of the cornea is to let light through and to focus it on the retina. If the cornea becomes cloudy or deformed because of a disease or accident, the projection of light onto the retina is affected. This has consequences for that eye’s vision. In such cases, a corneal transplant may be necessary.
A corneal transplant is an operation where part of the diseased or damaged cornea of the patient is removed. It is then replaced with a corresponding portion of healthy cornea from a donor. The transplant is generally performed to improve vision. Sometimes, it can also be used to reduce pain or maintain the structure of the eyeball, for instance after a tear in the cornea.
The physician decides which type of transplant is the best solution for you:
- penetrating keratoplasty (PKP): the cornea is replaced in its full thickness (that is, all layers)
- endothelial transplant (DSAEK): only the diseased, inner part (endothelium) of the cornea is replaced
If the decision is to perform a transplant, you will be placed on a waiting list. It may take some time before good donor tissue becomes available. The average waiting time is six months to, potentially, a year (in exceptional cases).
What is the process?
The donor tissue, also termed corneal graft, comes from a person who has passed away. The cornea is kept in the eye bank at our hospital until just before the implantation. Every donated cornea is thoroughly tested for infectious disease such as AIDS and hepatitis (B and C). Additionally, various tests are conducted to evaluate the quality of the cornea. The age of the donor is only one factor. It is in principle not necessary to match donor and recipient (patient) by HLA type (as done for heart or kidney transplants).
A corneal transplant is usually performed under a general anaesthetic. The operation is performed with the aid of a surgical microscope. The inner, diseased part of the cornea is removed through a tiny opening. Then, another opening (5 mm incision) is used to insert the corresponding portion of the donor cornea into the eye. The donor graft is kept in place by introducing an air bubble. You need to remain lying flat on your back and the air bubble will push the donor tissue against your own cornea, making the two stick together (like two glass plates). Very fine threads are used to close the openings and incisions. The corneal transplant itself takes approximately one hour.
Rejection of the donor cornea is always a possibiity, even years after the procedure. The risk of rejection is lowest during the first six months after the operation and highest six months to two years after the operation. Signs of rejection include:
- a red eye
- sudden deterioration of vision
- increased sensitivity to (bright) light
- sudden pain in the eye
If you notice one or several signs you need to contact the Eye Surgery Department as soon as possible by telephone (09 246 87 00) - so not by e-mail - or come to the A&E Department (09 246 98 00). You must always come to the hospital within 24 hours. Always state that you have had a corneal transplant and that you are experiencing one or more possible signs of rejection.
You may always contact the attending physician should you have any further questions.
Centres and specialist areas
Latest publication date: 05/02/2021
Supervising author: Dr Vanwynsberghe David