Question

Following perimetry image is suggestive of?

• A. Extension of blind spot
• B. Arcuate scotoma
• C. Reinee step defect
• D. Altitude Anopia

Hint:

A curved comma-shaped field defect arching from the blind spot around fixation is the classic glaucomatous arcuate scotoma.

Answer 1

The Correct Option is B

Step 1: Interpret the perimetry. Perimetry (visual field testing) maps areas of reduced sensitivity (scotomas) in the visual field. The image shown demonstrates a curved (arcuate / comma-shaped) region of field loss arching from the blind spot around the fixation point toward the nasal field - the classic pattern of a glaucomatous nerve-fibre-layer defect.

Step 2: Why arcuate scotoma (option B) is the answer. Because retinal nerve fibres run in an arcuate course around the macula (following the arrangement of arcuate/Bjerrum fibres), damage to a bundle of these fibres - as in glaucoma - produces a curved "arcuate scotoma" that starts at the blind spot and sweeps around fixation. This is the most characteristic and commonly tested early glaucomatous field defect, and it matches the curved comma-shaped defect on the perimetry shown.

Step 3: Why the other options are less correct. Extension of the blind spot is enlargement of the physiological blind spot (seen e.g. in papilloedema), appearing as a localised area around the blind spot rather than a long curved arc. Roenne's (Reinee) nasal step defect is a step-like difference in the field across the horizontal nasal meridian - a specific later glaucomatous sign - but the broad curved defect shown is best described as an arcuate scotoma. Altitudinal anopia/hemianopia is loss of the entire upper or lower half of the field along the horizontal midline, typical of anterior ischaemic optic neuropathy, which is not the curved arc shown.

Final answer: Option B - Arcuate scotoma. (Note: no printed answer key was available for this item; the answer is derived from the classic glaucomatous arcuate field pattern shown.)