Infraorbital nerve involvement on magnetic resonance imaging in European patients with IgG4-related ophthalmic disease: a specific sign.

Objectives To measure the frequency of infraorbital nerve enlargement (IONE) on magnetic resonance imaging (MRI) in European patients suffering from an IgG4-related ophthalmic disease (IgG4-ROD) as compared to patients suffering from non-IgG4-related ophthalmic disease (non-IgG4-ROD).