Question:medium
Altitudinal visual field defect is seen in?
Altitudinal visual field defect is seen in?
Show Hint
A field loss that respects the horizontal line points to the optic disc circulation.
Updated On: Jun 24, 2026
- Papilloedema
- Retinitis pigmentosa
- Anterior ischemic optic neuropathy
- Buphthalmos
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: Key clue - a defect bounded by the horizontal meridian (altitudinal) localises to the optic disc, because retinal nerve fibres and the disc blood supply are divided into superior and inferior territories.
Step 2: The disease that classically infarcts one of these halves is anterior ischemic optic neuropathy. Occlusion of the short posterior ciliary arteries starves the prelaminar and laminar disc, killing the fibres of the upper or lower segment and leaving the other intact.
Step 3: Presentation - abrupt, painless loss of vision with a swollen, often pale disc that evolves into optic atrophy. The arteritic form is driven by temporal arteritis, the non-arteritic form by crowded disc plus vascular risk factors such as severe anemia or hypotension after haemorrhage.
Step 4: Distractors - papilloedema only enlarges the physiological blind spot, retinitis pigmentosa narrows the field concentrically (tunnel vision), and buphthalmos is infantile glaucoma. None gives a horizontal step defect.
\[\boxed{\text{Anterior ischemic optic neuropathy}}\]
Step 2: The disease that classically infarcts one of these halves is anterior ischemic optic neuropathy. Occlusion of the short posterior ciliary arteries starves the prelaminar and laminar disc, killing the fibres of the upper or lower segment and leaving the other intact.
Step 3: Presentation - abrupt, painless loss of vision with a swollen, often pale disc that evolves into optic atrophy. The arteritic form is driven by temporal arteritis, the non-arteritic form by crowded disc plus vascular risk factors such as severe anemia or hypotension after haemorrhage.
Step 4: Distractors - papilloedema only enlarges the physiological blind spot, retinitis pigmentosa narrows the field concentrically (tunnel vision), and buphthalmos is infantile glaucoma. None gives a horizontal step defect.
\[\boxed{\text{Anterior ischemic optic neuropathy}}\]
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