A 60-year-old diabetic patient undergoes automated visual field testing. The pattern of field loss most characteristic of glaucomatous optic neuropathy (as opposed to other optic nerve diseases) is:
- A Altitudinal defect respecting the horizontal meridian
- B Central scotoma with preserved peripheral field
- C Arcuate (Bjerrum) scotoma with nasal step at the horizontal raphe ✓
- D Binasal hemianopia
Correct answer: C. Arcuate (Bjerrum) scotoma with nasal step at the horizontal raphe
Explanation
Arcuate (Bjerrum) scotoma with nasal step at the horizontal raphe is the hallmark glaucomatous field defect. It results from loss of retinal nerve fibre layer (RNFL) bundles in the superior and inferior arcuate zones, which meet at the horizontal raphe nasally causing a nasal step (Ronne's nasal step). Central scotoma is typical of toxic or nutritional optic neuropathies. Altitudinal defects occur in anterior ischaemic optic neuropathy. Binasal hemianopia is caused by bilateral nasal retinal compromise (e.g., bilateral carotid compression).
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.