The cornea is the clear front of the eye also known as the “window of the eye”. It is essential that it remains to be clear for the transmission and focusing of light and images onto your retina so that you can see properly. When the cornea is damaged or sick, it may have to be “replaced” with a corneal transplant once all medical treatment has been tried. A corneal transplant is often also known as a corneal graft.
There are several medical indications for a corneal transplant:
- Corneal scarring e.g. from corneal infections or sharp injuries
- Genetic corneal dystrophies e.g. lattice, granular or macular corneal dystrophies
- Abnormal corneal shape e.g. severe keratoconus
- Melting or perforation (the development of a hole) in the cornea e.g. in rheumatoid arthritis or from injuries
- Corneal swelling e.g. Fuchs endothelial corneal dystrophy
What happens with corneal transplantation
Corneal transplantation involves micro-surgically removing your diseased cornea as a small disc and replacing it with clear healthy donated tissue. A transplanted cornea is from someone who has kindly donated their eyes for transplantation after death. Because this transplanted cornea is form someone else, there is always a potential risk of transplant rejection. Anti-rejection eye drops or rarely tablets are used to reduce this risk. Occasionally these anti-rejection treatments are required lifelong.
There are several types of corneal transplantation:
The conventional type of corneal transplantation that is still needed for some severe corneal diseases involves transplanting all the layers of the cornea. This is called a penetrating keratoplasty (PKP) and is a full-thickness graft. The new cornea is sutured into place using very delicate microscopic surgery. Full visual rehabilitation after a PKP can take up to a year, during which you will be putting in eye drops and seeing your corneal specialist regularly to check the newly transplanted cornea.
More recent transplantation methods are used if they are suitable for your corneal disease as they are associated with faster visual recovery and reduced rates of transplant rejection.
These newer transplantation techniques include
- Deep anterior lamellar keratoplasty (DALK) in keratoconus. This involves transplanting the front layers of the cornea. This type of transplant also requires several stitches to secure the new cornea.
- DSAEK or DMEK corneal transplants involve replacing the back layer of the cornea in Fuchs endothelial corneal dystrophy. These two types of corneal transplants require air to be used in the eye to hold the transplant in place for a few days to give it time to attach on its own, instead of stitches.
Corneal transplantation is only undertaken by an experienced corneal surgeon who has thoroughly assessed you and who is trained to do not only the optimal surgery for you but also look after your eye closely after your eye surgery.