What is a corneal transplant?
The cornea is the transparent, outermost layer of the eye. Being transparent, it allows light into the eye thus, playing an important role in vision. If the cornea is diseased or damaged, it can distort and block light from entering the eye. This can cause significant loss of vision.
A cornea transplant is a surgical procedure where diseased or scarred corneal tissue is replaced with healthy corneal tissue from a donor. This can be done for a number of reasons.
- When the diseased cornea is causing poor vision, a transplant can be carried out to restore vision.
- If pain is caused by a diseased cornea, a cornea transplant may also relieve that symptom.
- Severe corneal disease can also cause perforation of the cornea. In such cases, a corneal transplant can be performed to restore the integrity of the eyeball
- In severe infections of the cornea which is not responding to medical treatment, your ophthalmologist may recommend surgery to remove the infection and prevent further spread.
There are two main types of cornea transplants, full thickness cornea transplant (also known as Penetrating Keratoplasty) and partial thickness cornea transplant (also known as Lamellar Keratoplasty).
Penetrating or full thickness transplants involve removing all layers of the diseased cornea from the patient and replacing it with a healthy donor cornea. In this procedure, sutures are sewn onto the graft to ensure proper placement of the tissue.
In Lamellar Keratoplasty transplants only the front or back portion of the cornea is replaced, depending on the diseased area. Deep Anterior Lamellar Keratoplasty (DALK) is a type of partial thickness surgery where only the front part of the recipient cornea needs to be replaced and not the entire cornea. Because only a section of recipient corneal tissue is removed, the risk of rejection is less likely and the eye is less vulnerable to injury and infection. Endothelial Lamellar Keratoplasty is carried out when the recipient’s outer cornea is healthy; however, the innermost layer (corneal endothelium) is diseased or injured. In this procedure, only the recipient’s endothelial layer is removed and replaced with healthy donor cornea. This procedure requires no sutures on the graft to keep it in place, allowing the recipient’s graft to heal much quicker. There is also a lower risk of infection or rejection and less induced astigmatism occurs.
Possible problems with corneal transplant
Graft rejection occurs when the body’s immune system sees transplanted tissue as something that shouldn’t be there and tries to get rid of it. This can occur in 3 out of every 10 patients transplanted.
Warning signs of your body trying to reject your cornea transplant include:
- Sensitivity to light
- Hazy vision
- Eye pain
Should you experience such symptoms after a transplant, see your corneal surgeon immediately. Your ophthalmologist might be able to stop the rejection with medicine.