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Summary Uveitis is an inflammation of the uveal tract, which lines the inside of the eye behind the cornea. Much of the uvea lies between the retina and outer sclera. The uveal tract has three parts: the iris, the ciliary body, and the choroid. Uveitis is categorized according to the part of the uveal tract that is affected. Anterior uveitis is an inflammation of the front part of the uveal tract; it includes inflammation of the iris (iritis) and inflammation of the iris and the ciliary body (iridocyclitis). Intermediate uveitis includes inflammation of anterior vitreous and the vitreous base overlying the ciliary body and peripheral retina-pars plana complex. Posterior uveitis is an inflammation of the part of the uveal tract behind the lens of the eye. It includes inflammation of the choroid (choroiditis) and inflammation of the choroid and retina (chorioretinitis). Uveitis that affects the entire uveal tract is called panuveitis or diffuse uveitis. Many cases will resolve rapidly, but a significant number of patients develop persistent disease with inflammatory damage to ocular structures resulting in severe visual impairment. The main causes of sight loss are cystoid macular edema, cataract, and glaucoma. For many years, uveitis was considered a single disease entity; therefore, the approach to treatment varied very little. As knowledge of the disease process grew and the immunologic and microbiologic testing increased the fact that uveitis entails a multitude of diseases became clear. Although some diseases are local ocular immune phenomena, many of them are systemic diseases with ocular manifestations. Because the spectrum of disease pathogenesis ranges from autoimmunity to neoplasia to viruses, the practitioner of uveitis requires an understanding of internal medicine, infectious diseases, rheumatology, and immunology.
Treatment of uveitis is based on trying to halt inflammation within the eye, reduce any ocular discomfort and stabilize or improve vision. Other treatment goals include reducing uveitis-associated complications, preventing primary ocular damage, limiting existing damage and minimizing therapy associated adverse effects. Corticosteroids are the mainstay of treatment of all types of uveitis, they may be used topically,
given systemically via an oral, intravenous or intramuscular route, or injected periocularly, or intraocular delivery of corticosteroids, e.g. Retisert and Ozurdex that shows a significant reduction in recurrence rate and improvement in visual acuity. In sight threatening disease, addition of second-line immunosuppressive agents as methotrexate, cyclosporine and cyclophosphamide may need to allow reduction of the dosage of systemic corticosteroids, controlling intraocular inflammation, reducing number of relapses and maintaining vision. Based on the increasing knowledge of the immune mechanisms that underlie autoimmune diseases, a number of biologic agents have been investigated for the treatment of uveitis. These biologic agents have different targets: (i) cytokines (i.e. infliximab, adalimumab, and etanercept, all targeting tumour necrosis factor alpha [TNF-α]); (ii) cytokine receptors (i.e. daclizumab directed against the interleukin [IL] - 2receptor); (iii) lymphocytes (i.e. alemtuzumab directed against all lymphocyte subsets). The efficacy of TNFα-targeted therapies in sight-threatening, otherwise treatment-refractory uveitis is an argument in favor of expanding the role of these agents in non-infectious ocular inflammation. Introduction of these agents earlier in the course of the disease may prevent the structural damage that results in permanent visual impairment. The rapid action of anti-TNFα agents could also be utilized as a rescue therapy in acute severe relapse, particularly in patients who have contraindications to high dose corticosteroids. Other biologic agents include, interferon- α (IFN-α) is used for refractory posterior Uveitis or Behçet’s disease, if the response to other agents is inadequate. It has also been used to treat patients with other causes of uveitis including, sympathetic ophthalmia, Vogt-Koyanagi-Harada disease, birdshot chorioretinopathy, intermediate uveitis, and idiopathic panuveitis.