Long-term follow up of systemic rituximab therapy as first-line and salvage therapy for idiopathic orbital inflammation and review of the literature

Purpose: To report long-term outcomes of systemic rituximab therapy for idiopathic orbital inflammation (IOI) as both primary and salvage therapy and to review the English literature. Methods: A retrospective review of four consecutive biopsy-proven IOI cases managed with systemic rituximab including demographics, management, and outcomes, and review of English literature, were performed. Primary outcome measures included resolution of symptoms, recurrence, and length of follow up. Results: Of four cases, systemic rituximab was the first-line therapy in two cases and salvage therapy in two cases. The mean age of the patients was 62 years (range, 50-68 years). The orbit was involved in three cases and extraocular muscle in one case. Systemic rituximab (1 g weekly for 4 weeks) was given for one session in three patients and for 12 sessions in 1 patient. All four patients responded with the resolution of all symptoms without recurrence after at least 5 years of follow up. Review of the literature showed systemic rituximab had provided clinical improvement at shorter follow up in 14 of 15 cases when used as a salvage therapy. Conclusions: Systemic rituximab therapy seems to be an effective therapy for IOI as salvage or first-line therapy with long-term clinical durability.