The cornea is the eye’s outermost layer. It is the clear, domeshaped surface that covers the front of the eye. It plays an important role in focusing your vision as it is responsible for transmitting light into the back of the eye.
What causes cornea problems?Eye disease and injuries can damage the cornea. Here are some common eye problems that can lead to a damaged cornea:
- Keratoconus, where the cornea is cone shaped rather than dome-shaped
- Fuchs’ dystrophy, where cells in the inner layer of the cornea are not working effectively
- Eye infections or injuries that scar the cornea
- Corneal abrasion is a scratch or scrape on the cornea.
- Corneal ulcer is an open sore on the cornea.
- Pterygium is a pinkish, triangular tissue growth on the cornea.
Corneal Surface Disease and Treatment
Photo-therapeutic Keratectomy (PTK) is used to treat corneal surface diseases and scars. PTK is not used to reduce dependency on glasses or contacts but rather to produce a smoother, clearer cornea.
Corneal Transplant overview
View Video If your cornea cannot be healed or repaired, your ophthalmologist may recommend a corneal transplant. This is when the diseased cornea is replaced with a clear, healthy cornea from a human donor.
Penetrating keratoplasty (PK) or full thickness cornea transplant replaces the entire cornea with a clear donor cornea. Getting complete vision back after PK may take up to 1 year or longer. With a PK, there is a slightly higher risk than with other types of corneal transplants that the cornea will be rejected. This is when the body’s immune system attacks the new cornea tissue.
Deep Anterior Lamellar Keratoplasty (DALK)
Partial thickness corneal transplant (deep anterior lamellar keratoplasty, DALK) replaces the front and middle layers of the cornea while keeping the endothelial layer, or thin back layer, in place. DALK is commonly used to treat keratoconus or bulging of the cornea.
Healing time after DALK is shorter than after a full cornea transplant. There is also less risk of having the new cornea rejected.
In some eye conditions, the innermost layer of the cornea called the “endothelium” is damaged. This causes the cornea to swell, affecting your vision. Endothelial keratoplasty is a surgery to replace this layer of the cornea with healthy donor tissue. It is known as a partial transplant since only this inner layer of tissue is replaced.
There are a few types of endothelial keratoplasty. They are known as:
DSEK (or DSAEK) Descemet’s Stripping Automated Endothelial Keratoplasty
DMEK Descemet’s Membrane Endothelial Keratoplasty
Each type removes damaged cells from an inner layer of the cornea called Descemet’s membrane. The damaged corneal layer is removed through a small incision. Then the new tissue is put in place. Just a few stitches—if any—are needed to close the incision. Much of the cornea is left untouched. This lowers the risk of having the new cornea cells being rejected after surgery.
Some things to know:
With DSEK/DSAEK surgery, the donor tissue may be easier to transplant and position because it is thicker than the donor tissue in DMEK surgery.
In DMEK surgery, the donor tissue is thin and can be more difficult to transplant. However, recovery is quicker because the transplant tissue is thinner.
Your eye surgeon will choose the type of surgery based on your cornea’s condition.
North Carolina EENT has offices in Cary, Durham, Chapel Hill, Roxboro for treatment of Cornea Disease.