Toxic/nutritional optic neuropathy typically presents with which type of visual field defect?

• A. Central scotoma
• B. Bitemporal hemianopia
• C. Altitudinal defect
• D. Homonymous hemianopia

Answer: (A)

Toxic/nutritional optic neuropathy tends to hit the fibers that subserve central vision, especially the papillomacular bundle. Because these macular fibers are affected first, you see a central scotoma on visual-field testing, often centrocecal in pattern, with peripheral vision relatively preserved early on. Patients commonly notice blurry vision and reduced color vision as well, reflecting macular involvement. Other field patterns—bitemporal hemianopia from a pituitary/chiasmal issue, altitudinal defects from ischemic optic neuropathy, or homonymous hemianopia from post-chiasmal disease—don’t fit this macular-predominant, bilateral central loss.