Homonymous hemianopia with macular sparing most reliably localises to which site?
- A Optic chiasm
- B Lateral geniculate body
- C Occipital cortex at the posterior pole ✓
- D Optic radiations in the temporal lobe
Correct answer: C. Occipital cortex at the posterior pole
Explanation
The occipital pole, where macular fibres terminate, receives a dual arterial supply from the posterior cerebral artery and terminal branches of the middle cerebral artery. Occlusion of the posterior cerebral artery therefore infarcts the calcarine cortex but spares the pole, preserving central vision. Macular sparing can also reflect bilateral cortical representation of the macula. Geniculate and radiation lesions produce congruous defects without sparing, which eliminates those options.
Reference: Parsons' Diseases of the Eye, 22nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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