[Imaging of neuro-ophthalmological emergencies].

MRI often is mandatory in the diagnostic work-up of visual loss, visual field alterations and oculomotor problems. It is performed emergently in patients with painful diplopia associated to mydriasis, to exclude aneurysm, or in patients with painful Horner syndrome to exclude dissection of the internal carotid artery. CT scan in emergency remains useful in case of acute lateral hemianopsia or acute post traumatic visual loss. Progressive neuro-ophthalmological symptoms may require imaging examination in a short delay to define the therapeutic strategy: monocular transient blindness (dissection or carotid stenosis), progressive visual loss (optic nerve compression), bitemporal hemianopsia (optic chiasm lesion), painful visual loss (optic neuritis). A very precise clinical indication is helpful for the choice of imaging protocol and to improve its diagnosis value.