Approach to a Patient with Diplopia in the Emergency Department

Unenhanced plain computed tomography (CT) of the head or orbits is largely not useful in the work-up of diplopia. Magnetic resonance imaging is preferred for ocular motor nerve palsies. Due to limited resources in the ED, patients with isolated fourth and sixth nerve palsies with the absence of other neurological signs on examination should be referred to Neurology or Ophthalmology for further work-up. All patients presenting with an acute isolated third nerve palsy should be imaged with CT and CT angiography of the brain to rule out a compressive aneurysm. Contrast-enhanced CT imaging of the brain and orbits would be indicated in suspected orbital apex syndrome or a retro-orbital mass, thyroid eye disease, or ocular trauma. CT and CT venogram should be considered in cases of suspected cavernous sinus thrombosis. In any patient over the age of 60 years presenting with recent (1 month) history of diplopia, inflammatory markers should be obtained to rule out giant cell arteritis.