A 58-year-old hypertensive man wakes up with sudden painless loss of the superior visual field in his left eye. Fundus examination shows pallid disc oedema in the inferior half of the optic disc and flame haemorrhages at the disc margin. The cup-to-disc ratio is 0.1. This is most consistent with:
- A Arteritic anterior ischaemic optic neuropathy (AAION — giant cell arteritis)
- B Optic neuritis — retrobulbar type
- C Leber's hereditary optic neuropathy
- D Non-arteritic anterior ischaemic optic neuropathy (NAION) ✓
Explanation
Non-arteritic AION presents in patients with vascular risk factors (hypertension, diabetes) as sudden painless altitudinal visual field loss, with sectoral or diffuse disc oedema and splinter haemorrhages. A small 'disc at risk' (small cup-to-disc ratio, crowded disc) is the primary anatomical predisposition because the tight scleral canal leaves no room for ischaemic swelling. AAION (GCA) occurs in patients >55 years, with ESR >50, jaw claudication, scalp tenderness, and causes chalky-white disc oedema with no haemorrhage; urgent high-dose steroids are needed. Optic neuritis shows pain on eye movement, RAPD, and central scotoma. Leber's HON is a bilateral, sequential optic neuropathy of young men with telangiectatic disc vessels and no haemorrhage.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
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Written and medically reviewed by the StethoPrep medical team.