The extent of inflammation that can occur in<unk>  is well demonstrated on magnetic resonance imaging (MRI). Infraorbital nerve enlargement (IONE) is considered to be a particularly suspicious sign of<unk> , but seems to occur only when inflammation is in direct contact with the infraorbital canal. IONE is defined as the infraorbital nerve diameter being greater than the optic nerve diameter in the coronal plane. Enlargements in the left inferior rectus muscle and infraorbital nerve (arrow) in a 65-year-old man with a serum<unk>  of 404 mg/dL. (T2-weighted MRI) Swelling of the left superior and lateral rectus muscles, a mass lesion around the left optic disc (arrow), and enlargements of the left supraorbital nerve and the right infraorbital nerve (arrow heads) in a 60-year-old man with a serum<unk>  of 463 mg/dL. (T1-weighted MRI) Bilateral supraorbital nerve enlargements (arrows) and right infraorbital nerve (arrow head) enlargement in a 47-year-old woman with a serum<unk>  of 1000 mg/dL. (T1-weighted MRI)
IgG4-related ophthalmic disease
Late congenital syphilitic oculopathy
Chronic relapsing inflammatory optic neuropathy
Intermediate uveitis
Graves' ophthalmopathy
Neurotrophic keratitis
Toxic and nutritional optic neuropathy
Idiopathic orbital inflammatory disease