Visual Field Deficit

Aka: Visual Field Deficit, Visual Field Defect, Hemianopia, Hemianopsia, Homonymous Hemianopia, Bitemporal Hemianopia, Binasal Hemianopia, Heteronymous Hemianopsia, Altitudinal hemianopsia, Quadrantanopsia, Quadrantanopia, Homonymous Quadrant Anopia

advertisement

II. Definitions

  1. Hemianopsia (Hemianopia)
    1. Partial or complete loss of Vision in one half of the Visual Fields of one or both eyes

III. Images

  1. visualFieldDefects.jpg

IV. Physiology

  1. Objects in the Visual Field are projected onto each eye's Retina as a mirror image
    1. Upper right Visual Field localizes to the lower left Retina of each eye
  2. Signals from each Retina follow the Optic Nerve to the Optic Chiasm, in the region of the Pituitary Gland
    1. Left Visual Field signals from each Retina (left medial and right lateral) join at Optic Chiasm
    2. Left Visual Field signals follow the Optic Nerve to the right Lateral Geniculate Body
    3. Right Lateral Geniculate Body signals follow right Optic Radiations
      1. Upper Visual Fields through the Temporal Lobe
      2. Lower Visual Fields through the Parietal Lobe)
    4. Signals terminate in the right Occipital Lobe visual cortex (Brodmann Area 17-19)
    5. Right Visual Fields are similarly routed to the left Occipital Lobe

V. Types: Unilateral Field Cuts

  1. Peripheral Vision Loss
    1. Glaucoma
    2. Retinal Detachment
  2. Central Scotoma
    1. Migraine Headache
    2. Macular Degeneration
    3. Demyelinating Disease (e.g. Multiple Sclerosis)
  3. Monocular Blindness
    1. Optic Nerve lesion
    2. Transient Monocular Blindness (Amaurosis Fugax, Central Retinal Artery Occlusion)

VI. Types: Bilateral Field Cuts

  1. Bitemporal Hemianopsia (Hemianopia)
    1. Visual Field loss in the lateral, temporal hemifields of both eyes
    2. Suggests Optic Chiasm lesion
  2. Binasal Hemianopsia (Hemianopia)
    1. Visual Field loss in the medial, nasal hemifields of both eyes
    2. Brain Mass
    3. Keratoconus
    4. Bilateral internal carotid aneurysms
    5. Neurosyphilis
    6. Optic Neuropathy
  3. Quadrantanopsia (Quadrantanopia)
    1. Loss of Vision in one quarter of the Visual Field in one or both eyes
    2. Altitudinal hemianopsia refers to Visual Field loss above or below the horizontal Meridian
    3. Localizes lesions to the Optic Radiations between the Lateral Geniculate Body and the visual cortex (Occipital Lobe)
      1. Parietal lesions affect the inferior Visual Field
      2. Temporal lesions affect the superior Visual Field
  4. Homonymous Hemianopsia (Hemianopia)
    1. Visual Field Defect with same half of Visual Field loss from each eye (left or right Visual Field)
    2. Occipital lesion

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Visual Field Deficit." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Related Studies

Related Topics in Symptoms

advertisement