What is a Corneal Scar?
The cornea is a clear, dome-shaped, protective covering over the iris (colored part of the eye) and the pupil (the small central black circle in the iris) of the eye. It plays a significant role in focusing light and helps you see clearly. Any form of damage to the corneal - abrasion, injury, infection, abnormal growth of tissue (epithelium) or keratoconus (irregularly shaped cornea) may cause corneal scars.
When injury to the deep layers of the cornea fails to heal completely, it results in the formation of scar tissue and leads to blurred or hazy vision due to a distorted cornea or obstruction in the visual field.
When you present to the clinic with these symptoms, your doctor may conduct a physical examination and order tests to examine your eyes. Your vision will be evaluated through a visual acuity test and your cornea will be examined through a slit lamp microscope.
Vision problems caused by corneal scars can be treated with prescription glasses or hard contact lenses. Alternatively, the following surgical techniques may be advised:
- Phototherapeutic keratectomy
Phototherapeutic keratectomy (PTK)
Superficial corneal scars can be effectively treated with PTK. In this procedure, the surgeon will remove the top layer of your cornea (epithelium) and use the excimer laser to treat the cornea. The laser removes tiny amounts of tissue to smoothen the corneal surface and improve vision. It also helps in reshaping the cornea. Antibiotic eye drops may be instilled to prevent infections and a bandage lens is placed over your eye for protection. PTK has the benefit of providing permanent results.
Corneal transplant procedures will be carried out depending on which part of the cornea needs to be replaced and will be performed under general or local anesthesia.
Full-thickness corneal transplants or penetrating keratoplasty
Penetrating keratoplasty involves the removal of the damaged corneal area and replacing it with a donated cornea. Your surgeon will use a circular cutting instrument called a trephine to cut through the thickness of the damaged cornea. The new cornea will be placed and sutured with tiny stitches around its edges.
Partial-thickness corneal transplants
The partial-thickness transplant involves the transplantation of only parts of the cornea. Based on the requirement, the front or back portion of the cornea will be transplanted and replaced with donor grafts.