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B27. Types of visual field defects

From greek.doctor

Vision is a complex process which involves many neurological structures. Different parts of the vision depends on different structures. As such, a great variety of visual field defects (areas of the visual field with defective or absent vision) can occur depending on which structure is affected.

Homonymous vision loss = same side is lost on both eyes. E. g. temporal half on left eye and nasal half on right eye

Heteronymous vision loss = opposing regions are lost. E. g. temporal half on left eye and temporal half on right eye

Hemianopia = loss of half the vision field

Quadrantanopia = loss of one quarter of the vision field

Types

  • Complete unilateral vision loss
    • Due to pre-chiasmal lesion (retina or optic nerve)
  • Bitemporal heteronymous hemianopia
    • = bilateral loss of temporal visual field
    • Due to lesion of the middle part of the optic chiasm
    • Fibres transmitting the nasal part of the visual field crosses in the optic chiasm
    • Fibres transmitting the temporal part of the visual field does not cross
  • Ipsilateral nasal hemianopia
    • = ipsilateral loss of nasal visual field
    • Due to lesion of the lateral part of the optic chiasm
  • Binasal heteronymous hemianopia
    • = bilateral loss of nasal visual field
    • Due to lesion of both lateral parts of the optic chiasm
  • Contralateral homonymous hemianopia
    • = loss of the ipsilateral nasal and contralateral temporal visual fields
    • Due to lesion of the optic tract
    • The optic tract transmits information from the ipsilateral nasal visual field and the contralateral temporal visual field
  • Contralateral homonymous upper quadrantanopia
    • = loss of ipsilateral upper nasal quadrant and contralateral upper temporal quadrant
    • Due to lesion of
      • Anterior part of optic radiation
      • Lower part of calcarine fissure
  • Contralateral homonymous lower quadrantanopia
    • = loss of ipsilateral lower nasal quadrant and contralateral lower temporal quadrant
    • Due to lesion of
      • Posterior part of optic radiation
      • Upper part of calcarine fissure
  • Contralateral homonymous hemianopia with central sparing
    • = loss of the ipsilateral nasal and contralateral temporal visual fields, but the central vision remains intact
    • Due to lesion of the occipital lobe