Corneal Abrasion Health Article

Definition

A corneal abrasion occurs when there is a loss of cells from the epithelium or surface of the cornea. It is usually due to trauma but may occur without trauma such as with the overuse of contact lenses.

Description

The cornea is the clear curved structure found at the front of the eye. It is comprised of three layers and the membranes that separate these layers. It is very difficult to penetrate past the epithelium or top layer of the cornea. The cornea is normally devoid of blood vessels yet has many sensory nerves. When any trauma to the corneal epithelium occurs, cells are lost or destroyed and pain is immediately sensed. When a corneal abrasion occurs, the conjunctiva, or the white of the eye, turns red, as new blood vessels form and those present enlarge, in an attempt to increase blood flow to the eye as it attempts to bring to the eye those cells needed for the healing of the cornea.

A corneal abrasion heals by the movement of neighboring epithelial cells, which slide over the wounded area, and through a cell division process called mitosis, which fill in the abraded area with new epithelial cells. Within two to three days of trauma to the cornea, these new cells start to adhere to the underlying membrane of the epithelium, called the basement membrane and within seven to eight days the abraded area usually heals completely without scarring. But if a corneal abrasion is deep and penetrates the next layer of the cornea, then scarring is possible and complete healing of the abrasion may be delayed as long as three months.

Demographics

Corneal abrasions account for 10 percent of ocular emergency care. The incidence of non-penetrating injuries to the eye, which includes corneal abrasions, is 1.57 percent per year. More males are treated for corneal abrasions than are females.