New developments in corticosteroid therapy for uveitis.

Corticosteroids remain the mainstay of the management of patients with uveitis. Topical corticosteroids are effective in the control of anterior uveitis, but vary in strength, ocular penetration and side effect profile. Systemic corticosteroids are widely used for the management of posterior segment inflammation which requires treatment, particularly when it is associated with systemic disease or when bilateral ocular disease is present. However, when ocular inflammation is unilateral, or is active in one eye only, local therapy has considerable advantages, and periocular injections of corticosteroid are a useful alternative to systemic medication and are very effective in controlling mild or moderate intraocular inflammation. More recently, the injection of intraocular corticosteroids such as triamcinolone have been found to be effective in reducing macular oedema and improving vision in uveitic eyes which have proved refractory to systemic or periocular corticosteroids. The effect is usually transient, lasting around 3 months, but can be repeated although the side effects of cataract and raised intraocular pressure are increased in frequency with intraocular versus periocular corticosteroid injections. This has led to the development of new intraocular corticosteroid devices which are designed to deliver sustained-release drugs and obviate the need for systemic immunosuppressive treatment. The first such implant was Retisert, which is surgically implanted (in the operating theatre) and is designed to release fluocinolone over a period of about 30 months. More recently, Ozurdex, a 'bioerodible' dexamethasone implant which can be inserted in an office setting, has completed phase III clinical trials in patients with intermediate and posterior uveitis. This implant lasts approximately 6 months, and has been found to be effective with a much better side effect profile than Retisert or intravitreal triamcinolone injection, at least for one injection.