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Cranial Nerve II
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Optic Nerve Clinical Notes and Interpretation

  • The patient must have intact cognitive abilities and the ability to cooperate in order to successfully accomplish the previously described examination tasks.
  • Visual acuity testing is typically performed with corrective lenses, if the patient commonly uses them, but can be performed without them.
  • Differences of more than one line in visual acuity should be referred to an ophthalmologist.
  • Macular degeneration, cataracts, and retinal disease may cause blind spots.
  • An optic nerve lesion will produce complete or partial blindness in the involved eye.
  • A complete lesion in one optic tract or in one lateral geniculate body results in blindness in opposite visual fields (i.e., nasal and temporal) of both eyes.
  • A temporal lobe lesion may produce blindness in the upper quadrants of both visual fields contralateral to the lesion.
  • A parietal lobe lesion may produce contralateral blindness in the lower quadrants of both eyes.
  • Occipital lesions cause contralateral changes with macular sparing.
  • Cortical blindness can also occur from occipital lesions, particularly to association areas.
  • Pre-chiasmatic lesions result in ipsilateral loss of vision (i.e., retinal tumors, masses affecting the optic nerve).
  • Chiasmic lesions result in bi-temporal hemianopsia (i.e., pituitary tumors, Berry aneurysm).

 

Point here to view typical visual field deficits

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Section: Cranial Nerve II
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Page 9 of 11
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