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NAION — SCE Neurology MCQ

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HardNeuro-ophthalmologyNAIONSCE Neurology

A 59-year-old wakes with painless monocular visual loss. Examination shows a relative afferent pupillary defect, a swollen segmental haemorrhagic optic disc and an inferior altitudinal defect. ESR, CRP and platelet count are normal and there are no giant-cell-arteritis symptoms. What is the most likely diagnosis?

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Correct answer: E — Non-arteritic anterior ischaemic optic neuropathy

The best answer is “Non-arteritic anterior ischaemic optic neuropathy”. Sudden painless altitudinal loss with a segmentally swollen disc in a vasculopathic patient is typical of NAION; absence of systemic GCA features and normal inflammatory tests lowers, but clinical judgement must still address, arteritis risk. “Demyelinating optic neuritis with central colour desaturation” is less appropriate because optic neuritis more often causes pain on eye movement and central colour loss in a younger patient “Papilloedema associated with raised intracranial pressure” is less appropriate because papilloedema is usually bilateral and initially preserves central acuity “Central retinal vein occlusion with venous engorgement” is less appropriate because retinal-vein occlusion produces widespread retinal haemorrhages and venous engorgement “Arteritic anterior ischaemic optic neuropathy from GCA” is less appropriate because arteritic disease is more often profound and chalky with supporting systemic or inflammatory evidence

Reference: Optic neuritis: a practical guide. https://pn.bmj.com/content/18/5/358