Idiopathic orbital inflammatory syndrome (IOIS) is a heterogeneous group of disorders characterised by orbital inflammation without any identifiable local or systemic causes. It is a rare clinical entity and a diagnosis of exclusion. Lymphomas, thyroid eye diseases or systemic diseases can have similar presentation and so, a histopathological diagnosis is considered important. IOIS is a difficult condition to treat. Compilation of reported small series of patients with IOIS suggested that they require multiple systemic immunosuppressant drugs and radiotherapy. Recently, a large monocentric study including patients with biopsy proven IOIS showed that up to 40% of them can relapse. Their clinical and pathological features did not correlate with treatments outcomes. The investigators decide therefore to conduct a multicentric retro/ prospective study to determine clinical features, histopathology and treatment outcomes of French patients with IOIS.
The purpose of this study is to characterise the clinical features, histopathology and the treatment outcomes of patients with idiopathic orbital inflammation syndrome.