A 45-year-old presents with a progressive superior altitudinal visual field defect with cup-to-disc ratio 0.4 and normal IOP. MRI brain is normal. Fluorescein angiography shows non-perfusion in the superior peripapillary region. The most likely diagnosis is:
- A Superior segmental optic hypoplasia (topless disc syndrome)
- B Normal tension glaucoma with superior arcuate defect
- C Non-arteritic anterior ischemic optic neuropathy (NAION) ✓
- D Branch retinal artery occlusion affecting the superior arcade
Explanation
NAION (non-arteritic anterior ischemic optic neuropathy) typically presents in middle-aged to elderly patients with acute, painless visual loss and superior altitudinal visual field defect. The pathophysiology involves ischemia of the posterior ciliary artery supply to the anterior optic nerve. FA shows delayed filling or non-perfusion of the superior disc segments. The 'disc at risk' (small disc with small cup, Cup:Disc < 0.3) is a major predisposing anatomic factor, though any CD ratio can be seen. NAION has an associated disc edema during the acute phase (sectoral hyperemia or pallid edema), which evolves to segmental optic atrophy. The IONDT (Ischemic Optic Neuropathy Decompression Trial) showed optic nerve sheath decompression was not beneficial.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.