Orbital Pseudotumor: Distinct Diagnostic Features and Management

PURPOSE: To provide an overview of the spectrum of diseases known as ‘idiopathic orbital inflammatory syndrome’ also known as orbital pseudotumor, with emphasis on specific diagnostic challenges in the evaluation and management of patients with this disorder. METHODS: Review of the relevant literature and summarize recent findings regarding the epidemiology, diagnosis, pathophysiology and treatment of orbital pseudotumor. RESULTS: Orbital pseudotumor is a benign intraorbital process confined to the orbit but extra orbital involvement can occur. It is among the 3(rd) most common orbital diseases along with thyroid orbitopathy and lymphoproliferative disorder and accounts for 5-10% of orbital processes. Clinically, orbital pseudotumor has been categorized as myositis, dacryoadenitis, anterior, apical and diffuse process. Patients may present with diplopia, conjunctival chemosis, proptosis or abnormal computed tomography scan (CT-scan) findings. Patients may also have associated optic neuropathy. Diagnosis is based on careful history, ultrasonography (U/S), CT-scan and magnetic resonance imaging (MRI) studies which may also provide prognostic information. Treatment consists of systemic corticosteroids in the form of oral or intravenous administration. Confirmation is made by orbital biopsy. In addition to radiation, cytotoxic agents, immunosuppressant, IV immunoglobulin, biological therapy, TNF-alpha inhibitor monoclonal antibody and Mycophenolate Moftil have been found to be useful in the management of refractory orbital pseudotumor. CONCLUSION: Understanding of the clinical features of patients with orbital pseudotumor, differentiating it from other orbital processes by use of imaging techniques and timely implementation of available treatment strategies may help prevent visual loss and associated morbidity from this condition.