Uveitis
Alternative names:
anterior uveitis; choroiditis; choroidoretinitis; granulomatous uveitis; iritis; nongranulomatous uveitis; posterior uveitis; retinitis
Definition:
An inflammation of the uveal tract which includes the iris, ciliary body, and the choroid of the eye.
Causes, incidence, and risk factors:
Uveitis affects the uvea, the layer between the sclera and the retina, which also includes the iris, the ciliary body, and the choroid. The uvea is the middle layer of the eye which is very vascular and supplies blood to the retina. Causes of uveitis can include allergy, infection, chemical exposure, trauma, or the cause may be unknown.
The most common form of uveitis is anterior uveitis which affects the iris. This condition may also be called iritis or nongranulomatous uveitis. The inflammation is associated with autoimmune diseases such as rheumatoid arthritis or ankylosing spondylitis. The disorder may affect only one eye and is most common in young and middle-aged people. A history of autoimmune diseases is a risk factor.
Posterior uveitis affects the back portion of the uveal tract and may involve the choroid cell layer or the retinal cell layer or both. This condition is also referred to as granulomatous uveitis, choroiditis, choroidoretinitis, or sometimes retinitis. Posterior uveitis usually follows a systemic infection; however, it is difficult to culture the organism within the eye so diagnosis is based on clinical and laboratory examination. Toxoplasmosis is one of the most common causes of congenital uveitis in infants.
The inflammation causes spotty areas of scarring that correspond to areas with vision loss. The degree of vision loss depends on the amount and location of scarring. If the central part of the retina, called the macula is involved, central vision becomes impaired.
Posterior uveitis, affecting one or both eyes, can be caused by any of the following:
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