Question

Altitudinal visual field defect is seen in?

• A. Papilloedema
• B. Retinitis pigmentosa
• C. Anterior ischemic optic neuropathy
• D. Buphthalmos

Hint:

A field loss that respects the horizontal line points to the optic disc circulation.

Answer 1

The Correct Option is C

Step 1: An altitudinal field defect respects the horizontal midline and wipes out the upper OR lower half of the field. This pattern points to disease of the optic nerve head, where the upper and lower halves are supplied by separate branches.

Step 2: Anterior ischemic optic neuropathy (AION) is local anoxia of the front part of the optic nerve from involvement of the posterior ciliary arteries. Because these vessels segmentally supply the disc, infarction of one half produces a permanent altitudinal defect, typically affecting two quadrants of either the superior or inferior field.

Step 3: AION causes sudden painless vision loss with disc swelling that later becomes optic atrophy. Causes include giant cell (temporal) arteritis, severe anemia, major haemorrhage and a neglected attack of acute angle-closure glaucoma.

Step 4: Papilloedema enlarges the blind spot, retinitis pigmentosa gives ring or tubular field loss, and buphthalmos is congenital glaucoma. None of these produces a horizontal altitudinal defect, so AION is correct.