Ophthalmologists perform more than 40,000 corneal transplants each year in the United States. Of all transplant surgeries performed today, corneal transplants are the most common and successful.
A healthy, clear cornea is necessary for good vision. If your cornea is injured or affected by disease, it may become swollen or scarred, and its smoothness and clarity may be lost. Scars, swelling or an irregular shape can cause the cornea to scatter or distort light, resulting in glare or blurry vision.
What is a corneal transplant?
The cornea is like the crystal covering a clock face. It is a clear, round dome covering the iris and the pupil. By helping to focus light as it enters the eye, the cornea plays an important role in vision. When the cornea becomes damaged, clouded or hazy, a corneal transplant procedure may be indicated.
With a corneal transplant, the damaged or unhealthy cornea tissue is removed and clear donor cornea tissue is put in its place.
What is DSEK?
Descemet's Stripping Endothelial Keratoplasty (DSEK) is a revolutionary new technique in corneal transplant surgery. With DSEK, only the diseased layer of the cornea is replaced as opposed to the full thickness of the cornea. This allows for much faster visual recovery when compared to traditional corneal transplant surgery. With DSEK, there are minimal if any stitches and patients recover within 3-4 weeks as opposed to 6 months to 1 year when the full corneal is replaced.
DSEK improves vision for patients with certain types of corneal diseases that cause clouding of the front, clear part of the eye such as Fuchs Endothelial Dystrophy or Pseudophakic Bullous Keratopathy. Refer to the links below for a video description of DSEK corneal transplant surgery.
When is a corneal transplant necessary?
There are many conditions that can affect the clarity of the entire cornea. For instance, trauma or injury to the cornea can cause scarring, as can infections. When vision cannot be corrected satisfactorily with eye glasses or contact lenses or painful swelling cannot be relieved by medications or special contact lenses, your doctor may recommend a corneal transplant. Loss of vision and pain and swelling can be caused by various issues such as:
- Corneal failure after other eye surgery such as cataract surgery
- Keratoconus, a steep curving of the cornea
- Heredity corneal failure such as Fuchs' dystrophy
- Scarring after infections, especially after herpes
- Rejection after a first corneal transplant
- Scarring after an injury
Corneal transplant surgical options
With traditional full corneal transplant surgery, known as penetrating keratoplasty, a circular portion is removed from the center of the diseased cornea. A matching circular area is removed from the center of a healthy, clear donor cornea, placed into position and sutured into place.
With an EK cornea transplant procedure, endothelial keratoplasty, or DSEK, only the abnormal inner lining of the cornea is removed. A thin disc of donor tissue containing the healthy endothelial cell layer is placed on the back surface of the cornea. An air bubble pushes the endothelial cell layer into place until it heals in an appropriate position.
With a lamellar corneal transplant procedure, the superficial layers of the cornea are removed and replaced with donor tissue. Sutures are used to secure the new tissue into place.
Potential risks and side effects of corneal transplants
Corneal transplants are rejected 5-30% of the time. The rejected cornea clouds and vision deteriorates. Most rejections, if treated promptly, can be stopped with minimal injury. Warning signs of rejection include:
- Persistent discomfort
- Light sensitivity
- Change in vision
Other complications may include:
- Swelling or detachment of the retina
All of these complications can be treated.
Astigmatism, an irregular curvature of the transplanted cornea, may slow the return of vision but can also be treated. Vision may continue to improve up to a year after surgery.