7.2 The following assessment  was made on the visual field testing of a patient who presented with impaired vision.

(The darkened halves of the fields indicate the area of impaired vision).

a) What does the visual field testing indicate?

b) List 3 likely anatomical sites of lesion which may result in this visual defect.

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College Answer

a) What does the visual field testing indicate?
Rt. homonymous hemianopia 

b) List 3 likely anatomical sites of lesion which may result in this visual defect.

Left optic tract
Left optic radiation
Left occipital lobe

Discussion

The localisation of visual field defects lends itself especially well to a massive insane-looking eyeball diagram, which I have put together many years ago in med school.

For detailed references, one can be directed to Chapter 116 by R.H Spector from Clinical Methods(1990), or "Topical diagnosis of chiasmal and retrochiasmal disorders" by Levin, from Walsh and Hoyt clinical neuro-ophthalmology, 6th ed.

Alternatively, one can explore this table cut-and-pasted from the Required Reading section (Visual fields and lesions of the visual pathways). As you can plainly see, one can put "tumour" down as a cause for pretty much any of these 

Lesions of the Visual Pathwas, with Clinical Correlations

Lesion

Localisation

Causes

Big blind spot

  • Retina
  • Optic nerve head
  • Optic nerve
  • Optic neuritis
  • Optic disk oedema (papilloedema)
  • Choreoretinitis

Tunnel vision

  • Optic nerve head
  • Optic nerve
  • Papilloedema
  • Optic neuritis involving external fibers

Central scotoma

  • Optic nerve
  • Papilloedema
  • Optic neuritis involving internal fibers

Unilateral blindness

  • Whole eye
  • Optic nerve (whole)
  • Involvement of the whole retina
  • Involvement of whole optic nerve:
    • Retinal artery occlusion
    • Retinal vein occlusion
    • Neuroma
    • Trauma
    • Tumour (retinublastoma)

Bitemporal hemianopia

  • Optic chiasm
  • Pituitary adenoma
  • Glioma
  • Medial sphenoid ridge meningioma
  • Aneurysms near the sella turcica
  • Ectatic ACA

Homonymous hemianopia

  • Optic Tract
  • Anterior choroidal artery infarction
  • Multiple sclerosis (or other demyelinating disease)
  • Trauma
  • Tumour
  • Lateral geniculate nucleus

Richly vascularised; difficult to take out with one ischaemic stroke: anterior choroidal artery and lateral geniculate artery are both involved in blood supply.

  • Pontine myelinolysis
  • Trauma
  • Syphilitic arteritis
  • Tumour
  • Optic radiation
  • Internal capsule stroke (eg. basilar artery)
  • MCA stroke (lenticulostriate arteries)
  • Haemorrhage
  • Tumour
  • Occipial lobe (extensive)
  • PCA stroke
  • PRES (posterior reversible encephalopathy)
  • Trauma
  • Tumour

Homonymous hemianopia with macular sparing

  • Occipial lobe (limited)
  • PCA stroke
  • PRES (posterior reversible encephalopathy)
  • Trauma
  • Tumour

Superior quadrantinopia

  • Temporal fascicle of optic radiation
  • Anterior temporal lobe damage: less likely to be vascular.
    • Infection (eg. mastoiditis leading to brain abscess)
    • Trauma (eg. SDH)
    • Tumour

Inferior quadrantinopia

  • Parital fascicle of optic radiation
  • Parietal lobe stroke (PCA)
  • Haemorrhage
  • Tumour

References

Levin, Leonard A. "Topical diagnosis of chiasmal and retrochiasmal disorders."Walsh and Hoyt clinical neuro-ophthalmology, 6th ed. Baltimore: Williams & Wilkins (2005): 503-573.

Robert H. Spector. "Visual Fields." (1990). Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.