Corneal surgery
Corneal Eye Care
The cornea is known as the window to the eye; it is the clear tissue that covers the colored portion of the eye. It plays an important role in focusing vision. It is exposed to light, touch and environmental factors that may damage the cornea and affect vision. Some of these conditions include corneal abrasion, conjunctivitis, corneal edema, and keratoconus.
Corneal Transplants
Corneal transplants, known as keratoplasty, are done by transfer of the clear central part of the cornea from a donor’s eye to the patient’s eye. Complete visual rehabilitation may take up to a year, but because the cornea contains no blood vessels, there are relatively few problems with tissue rejection. A corneal transplant can restore vision, reduce pain and improve the appearance of a damaged or diseased cornea.
A number of conditions can be treated with a corneal transplant, including:
- Keratoconus (cornea that bulges outward)
- Fuchs’ dystrophy
- Thinning of the cornea
- Corneal scarring, caused by infection or injury
- Clouding or swelling of the cornea
- Corneal ulcers, including those caused by infection
- Complications caused by previous eye surgery
Types of Corneal transplant surgery:
Penetrating keratoplasty – The surgeon cuts through the entire thickness of the diseased cornea, removes it, and replaces it with a donor cornea that is stitched into place. The stitches may be removed at a later date. An artificial cornea (keratoprosthesis) may be used in patients not eligible for a donor cornea.
Endothelial keratoplasty (EK) – This procedure replaces diseased tissue from the back layers of the cornea only, instead of replacing the full thickness of corneal tissue. The most common type of EK is called Descemet Stripping Endothelial Keratoplasty (DSEK).
Anterior Lamellar Keratoplasty (ALK) – This procedure replaces diseased tissue from the front corneal layers only, and may be performed on superficial (SALK) or deep layers (DALK), depending on the level of corneal damage present.
Most corneal transplant patients will have their vision at least partially restored. Results vary depending on the reason for your surgery and your health. Your vision may initially be worse than before your surgery as your eye adjusts to the new cornea. It may take several months for your vision to improve. Once the outer layer of your cornea has healed (several weeks to several months after surgery), your surgeon will work to make adjustments that can improve your vision, such as correcting unevenness in the cornea and correcting vision problems with glasses, contact lenses or laser eye surgery.
Pterygium
A pterygium is a wedge-shaped elevated growth on the cornea (the clear front window of the eye). It is a benign growth that starts on the sclera (the white part of the eye) and extends toward the center of the eye. It is a result of a process in which the conjunctiva grows into the cornea. It contains blood vessels and can form scar tissue that can permanently disfigure the eye.
The causes of pterygia are not totally understood. Long term exposure to UV-light (sunlight) and dry environmental conditions have been linked to their development. They seem to develop more often in people who spend a lot of time outdoors. Exposure to sun, wind, dust, and harsh climates are frequently correlated with pterygia. They also occur more often in men than women.
While the pterygium is growing, it becomes swollen and red. This growth process is slow, and it usually stabilizes without causing problems. Although the symptoms are not severe, growth over the central cornea may cause vision loss.
Once the pterygium invades the cornea and begins to threaten vision, it can be removed surgically. Surgery can also be performed for cosmetic reasons. However, pterygia have a tendency to return, especially in younger people. At times, dryness and irritation persist even after removal. Radiation and topical medications can be used to prevent recurrence.