Episcleritis

Definition:

An inflammation of the episclera, a membrane covering the sclera of the eye.

Causes, incidence, and risk factors:

The sclera is composed of collagenous fibers to form a white, hollow ball. It is the skeleton of the eyeball and is covered by the episclera, a thin layer of tissue containing many blood vessels that nourish the sclera. On the front of the eye, the episclera is covered by the conjunctiva. Inflammation of the episclera is usually mild and usually does not progress to scleritis. The cause is unknown, but certain diseases such as rheumatoid arthritis, Sjogren's syndrome, syphilis, herpes zoster, and tuberculosis have been associated with episcleritis. It is a common condition.