Uveitis Associated with Juvenile Idiopathic Arthritis

Uveitis is a potentially sight-threatening complication of juvenile idiopathic arthritis (JIA). JIA-associated uveitis is recognized to have an autoimmune aetiology characterized by activation of CD4(+) T cells, but the underlying mechanisms might overlap with those of autoinflammatory conditions involving activation of innate immunity. As no animal model recapitulates all the features of JIA-associated uveitis, questions remain regarding its pathogenesis. The most common form of JIA-associated uveitis is chronic anterior uveitis, which is usually asymptomatic initially. Effective screening is, therefore, essential to detect early disease and commence treatment before the development of visually disabling complications, such as cataracts, glaucoma, band keratopathy and cystoid macular oedema. Complications can result from uncontrolled intraocular inflammation as well as from its treatment, particularly prolonged use of high-dose topical corticosteroids. Accumulating evidence supports the early introduction of systemic immunosuppressive drugs, such as methotrexate, as steroid-sparing agents. Prospective randomized controlled trials of TNF inhibitors and other biologic therapies are underway or planned. Future research should aim to identify biomarkers to predict which children are at high risk of developing JIA-associated uveitis or have a poor prognosis. Such biomarkers could help to ensure that patients receive earlier interventions and more-potent therapy, with the ultimate aim of reducing loss of vision and ocular morbidity.