Uveitis is an inflammation of a part or all of the uvea which is a layer of tissue inside the eye consisting of the iris (the structure surrounding the pupil which gives the eye its brown, hazel or blue colour), the ciliary body (a ring-like structure behind the iris to which the lens is attached) and the choroid (the layer in the back of the eye on which the retina lies).
Uveitis may affect any part of the uvea or more than one part. Anterior uveitis mainly involves the iris (iritis). Cyclitis affects mainly the ciliary body. Posterior uveitis affects the choroid (choroioditis). When the retina is affected together with the choroid, the condition is called chorioretinitis. When all parts of the uvea are involved, the condition is called panuveitis.
Uveitis may occur in one or both eyes. Most patients are between the ages of 20 – 50 years.
It may appear suddenly as an acute condition or develop gradually. It may recur after a long interval.
Signs and symptoms of uveitis:
Pain, especially in anterior uveitis.
Redness, sensitivity to light and reduced vision.
The inflammation may affect other parts of the eye: the lens causing cataract, the drainage channels causing glaucoma and the retina causing blurred vision.
Uveitis may be part of a generalized disease such as rheumatoid arthritis, multiple sclerosis, autoimmune diseases such as Lupus, Behcet's disease, psoriasis, sarcoidosis. It may also be associated with inflammatory conditions of the digestive tract and with infectious diseases such as tuberculosis, Reiter's disease, toxoplasmosis, AIDS and herpes. In some malignant conditions such as lymphoma, the eye may show signs similar to uveitis. In many cases the disease is confined to the eye and no systemic cause can be found.
Examination of the eye with the slit lamp microscope will reveal inflammatory cells in the affected parts of the eye. Change is the retina and the optic nerve may be seen. The intraocular pressure may be elevated. The vision may be affected to varying degrees – sometimes seriously.
Blood tests and x-rays are performed in order to eliminate the various systemic diseases mentioned earlier.
The symptoms are relieved by the use of steroids. In anterior uveitis steroid eye drops are effective. Posterior uveitis is treated with systemic steroids, usually given by mouth. It is also possible to inject steroids into the tissues near the eye. Eye drops containing atropine-like drugs are used to dilate the pupil in order to prevent adhesion of the iris to the lens and in order to reduce pain. Very mild cases may clear up without the use of steroids.
If the intraocular pressure is raised, suitable treatment is given to control it. If the prolonged use of steroids causes side effects, chemotherapeutic drugs may be used instead. If any systemic disease is found it is treated.
In most cases the uveitis responds well to treatment an leaves no after effects. If the condition continues for a long time or recurs frequently, complication which have to be treated may occur, such as cataract, glaucoma and damage to the retina.