Corneal Abrasion
Scratching the cornea of the eye with a fingernail, a twig, a piece of paper, or some other foreign object is a painful occurrence known as corneal abrasion. In an episode of corneal abrasion, the corneal epithelium (a protective layer of cells which covers the outer surface of the cornea) becomes damaged. In addition, the basement membrane (a sticky layer which attaches the epithelium to the cornea) is often damaged as well.
Although the cells of the corneal epithelium heal within 48 hours, it takes from 6 to 8 weeks for a new basement membrane to form. The epithelial cells are only loosely attached to the cornea while the basement membrane is regenerating. In fact, the epithelial cells adhere better to the eyelids than to the damaged basement membrane. As a result, the new epithelial cells tend to be torn off the sensitive cornea each morning when the eye is opened.
Symptoms:
- Sharp pain (especially upon waking)
- Sensitivity to light
- Gritty, sandy, or foreign body sensation in the eye
Treatment:
The goal in treating corneal abrasion is to keep the healing cells from being pulled off the eye (recurrent corneal erosion). To achieve this goal, artificial tears are used to keep the eye well lubricated. Special drops and ointments are also prescribed to help keep the basement membrane and the corneal epithelium together. Additionally, the eye may be patched for a period of time to promote healing.
