IgG4-Related Orbital Disease

IgG4 related disease (IgG4-RD) is a systemic fibro-inflammatory disease leading to tumour-like infiltrations potentially affecting all parts of the human body, including the periorbital tissues (IgG4-ROD). IgG4-ROD mimics many infectious, inflammatory and malignant disorders. Therefore, the diagnostic gold standard is histopathology, however, serum IgG4 and the clinical presentation may be supportive in establishing the diagnosis. Glucocorticoids are the preferred first-line systemic treatment of IgG4-ROD. In severe refractory or vision threatening disease, rituximab combined with glucocorticoids is started. When refractory, cyclophosphamide can be initiated. In less severe cases, mycophenolate mofetil or infliximab can be considered as maintenance or steroid-sparing therapy. Radiotherapy or surgery may be indicated in localized refractory disease in patients with compressive optic neuropathy or proptosis.