Overview

• By identifying loss of vision in a particular field or group of fields, it is possible to localise an intracranial lesion and guide further investigation.
• The visual fields extend 100 degrees laterally, 60 degrees medially, 60 degrees upward and 75 degrees downward.

• • How to Assess

  • Ask the patient to cover one eye. Slowly move a finger or white examination pin from the upper left, upper right, lower left and then lower right, asking the patient to state when they can see the finger / pin. Repeat with the other eye.

• • Interpretation

  • Unilateral anopia - complete loss of vision in one eyeUnilateral optic nerve lesion or ocular pathology
  • Bitemporal hemianopia - loss of lateral vision in both eyesOptic chiasmal compression
  • Homonymous hemianopia - loss of left or right field in both eyesContralateral optic tract lesion
  • Homonymous inferior quadrantanopia - loss of the left or right lower quarters of vision in both eyesContralateral lower optic radiation lesion
  • Homonymous superior quadrantanopia- loss of the left or right upper quarters of vision in both eyesContralateral upper optic radiation lesion
  • Homonymous hemianopia with macular sparingContralateral occipital lobe lesion