Idiopathic orbital inflammation successfully treated using rituximab in a patient with rheumatoid arthritis.

To the Editor: Idiopathic orbital inflammation (IOI) is an orbital inflammatory disease, the third most common cause of inflammation within the orbit1. Although its etiology is unknown, there is said to be an association with an immune response directed against specific target tissues in the orbit2. In many autoimmune diseases, a cellular infiltrate is seen in the affected organ or tissue. Typically, the infiltrate consists of lymphocytes and monocytes, although other immune-related and inflammatory cells can also be seen3. We describe a case of IOI within a background of rheumatoid arthritis (RA), and its successful treatment with rituximab (RTX), a chimeric monoclonal antibody against CD20+. A 43-year-old woman with a 17-year history of seropositive RA presented with a 4-month history of diplopia, right-side proptosis and ptosis, a restriction of movement in the right eye, and a reduction in vision (Figure 1A). RA was very well controlled with adalimumab, an anti-tumor necrosis factor (anti-TNF) biologic agent, which she had been … Address correspondence to I. Ibrahim; E-mail: ibrahim.ibrahim{at}student.manchester.ac.uk