Definition
Episcleritis is irritation and swelling (inflammation) of the episclera, a thin layer of tissue covering the sclera of the eye.
Overview, Causes, & Risk Factors
The sclera is made up of of tissue fibers that form the strong white wall of the eye. It is covered by the episclera, a thin layer of tissue that contains many blood vessels that feed the sclera.
Episcleritis is inflammation of the episclera that occurs without an infection. It is a common condition that is usually mild and rarely progresses to scleritis.
The cause is usually unknown, but it may occur with certain diseases, such as:
- Herpes zoster
- Rheumatoid arthritis
- Sjogren syndrome
- Syphilis
- Tuberculosis
Pictures & Images
External and internal eye anatomy
The cornea allows light to enter the eye. As light passes through the eye the iris changes shape by expanding and letting more light through or constricting and letting less light through to change pupil size. The lens then changes shape to allow the accurate focusing of light on the retina. Light excites photoreceptors that eventually, through a chemical process, transmit nerve signals through the optic nerve to the brain. The brain processes these nerve impulses into sight.
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Episcleritis : Overview, Causes, & Risk Factors
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Episcleritis : Symptoms & Signs, Diagnosis & Tests
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Episcleritis : Treatment
Review Date : 10/27/2009
Reviewed By : Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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