الفهرس 
Anatomy of the uveal tractOnly 14 pages are availabe for public view
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Abstract
Uveitis, which is derived from uvea (Latin for grape) is defined as an inflammation of the uveal tract (iris, ciliary body, and choroid). Uveitis is a general term used to describe inflammation of the uveal tract, which is the middle layer of the eye, between the sclera, conjunctiva and the anterior chamber on the outside and the retina on the inside. Uveitis is categorized by location as follows: • anterior when it involves the iris or the ciliary body (iritis of iridocyclitis), • intermediate when the inflammation is limited to the vitreous, peripheral retina, pars plana or the ciliary body, • posterior when it affects the choroid or, by extension, the retina (choroiditis or retinochoroiditis). Posterior uveitis may or may not develop into retinal vasculitis or • panuveitis when two or more of these segments are affected. Details of the location, clinical course and laterality, in conjunction with the patient’s symptoms, are essential to establish the correct diagnosis in patients with uveitis.
Anterior uveitis remains the predominant manifestation of uveitis and HLA-B27 spondyloarthropathy-related anterior uveitis is the most common systemic association in most countries.
Acute anterior unilateral uveitis (AAU) is the most common form of uveitis, and it can be present in up to 40% of patients with SpA.
Uveitis may develop following eye trauma or surgery, in association with diseases which affect other organs in the body, or may be a condition isolated to the eye itself. Severe and permanent visual loss can result from uveitis. In addition, uveitis can lead to other ocular complications, which may produce vision loss, including glaucoma, cataracts, or retinal damage. Early detection and treatment is necessary to reduce the risk of permanent vision loss.
Uveitis is thought to be caused by an immune reaction . Anterior non granulomatous acute uveitis is associated with a variety of HLA-B27 related condition, including Ankylosing spondylitis, Reiter’s syndrome, Psoriasis, Ulcerative colitis and Crohn’s disease. Granulomatous anterior and posterior uveitis is associated with Behcet’s syndrome, TB and Toxoplasmosis. Posterior uveitis is associated with autoimmune retinal vasculitis.
The diagnostic modalities available to clinicians for the evaluation of uveitis have continued to improve over the last decade with increasingly sophisticated laboratory testing (e.g., polymerase chain reaction [PCR], cytokine evaluation, flow cytometry) and ophthalmic imaging techniques (e.g., fundus autofluorescence [FAF], three-dimensional spectral domain optical coherence tomography [OCT]).
Corticosteroids have been the mainstay of therapy for uveitis. Corticosteroids may be administered either topically, as periocular injections, or systemically (primarily orally but also by the intravenous or intramuscular route). Topical corticosteroids penetrate well only into the anterior segment of the eye and are useful in the management of anterior uveitis. Periocular corticosteroids are useful in the management of intermediate uveitis associated with decreased vision, the management of macular edema in association with panuveitis or posterior uveitis.
Sight-threatening noninfectious uveitis often requires long-term systemic immunosuppression to maintain visual function. This typically entails treatment with glucocorticoids, augmented by various combinations of T-cell inhibitors (e.g., cyclosporine and tacrolimus), antiproliferative agents (e.g., methotrexate, azathioprine, and mycophenolate mofetil [MMF]), and biologics (e.g., anti-tumor necrosis factor (TNF)-α, anti-CD25, and interferon-α).