page_title: Visual pathway lesions
section_title: Signs and symptoms
hierarchical_section_title: Visual pathway lesions / Optic chiasm lesions / Signs and symptoms
caption_attribution_description: English: Goldmann visual field record showing a bitemporal hemianopia
context_page_description: The visual pathway consists of structures that carry visual information from the retina to the brain. Lesions in that pathway cause a variety of visual field defects. In the visual system of human eye, the visual information processed by retinal photoreceptor cells travel in the following way:
  Retina→Optic nerve→Optic chiasm →Optic tract→Lateral geniculate nucleus→Optic radiation→Primary and secondary visual cortices.
  The type of field defect can help localize where the lesion is located.
context_section_description: A lesion involving complete optic chiasm, which disrupts the axons from the nasal field of both eyes, causes loss of vision of the right half of the right visual field and the left half of the left visual field. This visual field defect is called as bitemporal hemianopia.
  Anterior chiasmal syndrome, the lesions that affect the ipsilateral optic nerve fibres and the contralateral inferonasal fibres located in the Willebrand knee produce junctional scotoma, i.e., a combination of central scotoma in one eye and temporal hemianopia defect in the other eye.
  Middle chiasmal syndrome, the lesions involving the decussating fibres in the body of chiasma produce bitemporal hemianopia.
  Posterior chiasmal syndrome, the lesions affecting the caudal fibres in chiasma produce paracentral bitemporal field defects. Homonymous hemianopia on the contralateral side may occur when posterior chiasmal lesions involve the optic tract.
  Lateral chiasmal lesions may produce binasal hemianopia.
  Lesions at the junction of the optic nerve and chiasm may produce an ipsilateral monocular temporal scotoma known as 'junctional scotoma'.  Scottish ophthalmologist Henry Moss Traquair first identified and named this field defect.
caption: Visual field-bitemporal hemianopia
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