• left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract

• homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior)

• incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex

  https://www.youtube.com/watch?v=6zpTOci_1_Y

Homonymous hemianopia

• incongruous defects: lesion of optic tract/radiation (more anterior)
• congruous defects: lesion of occipital cortex (lesion more posterior)
• macula sparing: lesion of occipital cortex

Homonymous quadrantanopias

• superior: lesion of the inferior optic radiations in the temporal lobe (Meyer's loop)
• inferior: lesion of the superior optic radiations in the parietal lobe
• mnemonic = PITS (Parietal-Inferior, Temporal-Superior)
  • Inferior and superior here refer to the quadrantanopia itself

Bitemporal hemianopia

• lesion of optic chiasm
• upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour
• lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma