Abstract

Purpose: To characterize the clinical and pathological features of 24 patients with biopsy proven Idiopathic Orbital Inflammatory Syndrome (IOIS).

Methods: Retrospective case series

Results: The study included 14 men and 10 female patients, ranging in age from 14 to 75 years. The presenting symptoms and signs included pain (14/24), swelling/mass (19/24), diplopia (9/24), proptosis (15/24), extraocular muscle restriction (13/24), decreased vision (5/24) and ptosis (4/24). Histopathology was varied and included classical orbital pseudotumour (9/24), sclerosing orbital pseudotumour (13/24), vasculitic orbital pseudotumour (1/24) and granulomatous orbital pseudotumour (1/24). Treatments included oral steroids (19/24), intravenous steroids (1/24), methotrexate, azathioprine, mycophenalate and cyclosporin. Forty two percent of the patients had recurring episodes during the follow up period with 29% of patients requiring 2 or more treatment regimens to maintain remission. Two thirds of patients (16/24) had complete resolution of their symptoms and signs. There was no correlation between the histopathological subtype, relapse rate or symptoms and signs resolution.

Conclusion: Idiopathic Orbital Inflammatory Syndrome has variable clinical and pathological features. Although in some patients symptoms and signs resolve spontaneously most require treatment with oral steroids and additional immunosuppressant drugs or radiotherapy. The clinical and pathological features do not correlate with treatment outcomes.