The diagnostic value of the IDEAL-T2WI sequence in dysthyroid optic neuropathy: a quantitative analysis of the optic nerve and cerebrospinal fluid in the optic nerve sheath.

• The water fraction of the optic nerve and optic nerve subarachnoid space (ONSS) are greater in patients with dysthyroid optic neuropathy (DON) than in patients with thyroid-associated ophthalmopathy (TAO) without DON. • The optic nerve and the cerebrospinal fluid in the optic nerve sheath measures are associated with visual dysfunction. • The water fraction of the optic nerve and ONSS may be promising imaging markers for diagnosing DON.