Infraorbital Nerve Involvement on Magnetic Resonance Imaging in IgG4-related Ophthalmic Disease

Inclusion criteria : * Patient aged 18 and older treated in Fondation Rothschild (tertiary ophthalmology facility, Paris, France) from January 2006 through April 2015 * Presence of a clinical orbital inflammation: mass/swelling, pain, exophthalmos, visual loss, ptosis, or diplopia. * The presence of at least one pretherapeutic MRI confirming the inflammation of one or more orbital structures: the lacrimal gland, fat, muscles, or infraorbital nerve. The mandatory minimal MRI protocol include the following sequences: T1- and T2-weighted MRI image, in the transverse and coronal plane, and a fat-suppressed T1-weighted image in the coronal plane obtained after intravenous administration of a gadolinium chelate. * Completion of at least one orbital biopsy with a pathologic examination and an immunohistochemical screen for IgG4. Exclusion criteria : * Clinical and biological signs of thyroid-associated orbitopathy * Histologically proven lymphoma * Pretherapeutic MRI that is insufficient for an adequate interpretation * Absence of IgG4 testing in the pathology examination