When Cornea transplant needed?
If your cornea no longer lets light enter your eye properly because of scarring or disease, you may need a transplant. Your doctor will call it a keratoplasty. During the procedure, an eye surgeon removes a portion of your cornea and replaces it with a new section from a donor.
What Does Your Cornea Do?
This clear tissue covers the front of each eye. Light passes through it to enter your eye, then goes through your pupil (the dark spot at the center of the eye), and then through the lens.
Your cornea has to be clear and normally shaped for you to see properly. A number of things can damage it and affect your vision:
- Scars from trauma and infection.
- Keratoconus: This condition causes your cornea to get thin and lose its shape.
- Inherited conditions like Fuchs’ dystrophy, lattice dystrophy, and others.
What Are the Types of Cornea Transplants?
There are several different procedures:
Lamellar cornea transplant: The surgeon transplants selected layers.
Posterior lamellar or endothelial (EK) cornea transplant: The doctor transplants the deepest layers, including the endothelium.
Descemet’s stripping automated endothelial keratoplasty (DSAEK): The doctor removes your Descemet’s membrane and endothelium. He replaces it with the donor’s endothelium and stroma (the cornea’s thickest layer).
Descemet’s membrane endothelial keratoplasty (DMEK): The doctor removes your Descemet’s membrane and endothelium. He replaces it with the donor’s endothelium and Descemet’s membrane, but not the donor stroma. Or the surgery can include layers close to the surface (anterior lamellar cornea transplant).
Lamellar transplants are less invasive and generally have faster recovery than full-thickness transplants. They may be a better option when your problem is limited to certain layers of your cornea.
How Are Full-Thickness Transplants Performed?
The surgery can be done using local anesthesia. The doctor will give you medication to numb the eye and keep it still. You’ll be awake but sedated.
Another option is general anesthesia. The doctor will put you under during the procedure.
The surgeon uses a special tool called a trephine, which works like a cookie cutter. It removes a round section of damaged cornea from the front of your eye.
He uses the same process to remove a similar-sized circle from the donor’s eye. He places the new section of cornea onto your eye. Then he sews it into place with ultra-thin stitches.
What’s the Success Rate?
Experts know more about the long-term success rates of full thickness cornea transplants. How well they work depends on the root cause. For example, research has found that the new cornea lasts for at least 10 years in:
- 89% of people with keratoconus
- 73% of people with Fuchs’ dystrophy
- 60% to 70% of people with corneal scarring
What’s the Recovery Process Like?
You probably don’t have to worry that your body will reject the transplant. It only happens in a few cases. And you don’t have to be matched to a donor because the cornea is what your doctor will call an immunologically privileged part of the eye. That means your immune system is less likely to reject the new tissue. You’ll also get steroid eyedrops to prevent problems. Your body is even less likely to reject the transplant if only the outer layers are replaced.
The chances that you’ll have complications also depends on how many layers are transplanted. They can include:
- Bleeding (this is rare)
- Cataracts, retinal detachment, and damage to other parts of the eye
- Leakage of fluid from the transplant incision
- Infection (this is rare)
- Vision problems. Full thickness transplants can result in astigmatism, nearsightedness, and farsightedness. You might need glasses or contact lenses.
The same problem that damaged your old cornea could also harm the new one. For example, you could get a herpes simplex infection in the transplant.
The cornea tends to heal slowly. To keep it safe after the surgery, your doctor may ask you to wear a protective shield over your eye.