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SYMPTOMS
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Palinopsia, Visual hallucinations, Vision loss Right sided homonymous hemianopia: Difficulty seeing next letter or word
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Left sided homonymous hemianopia: Difficulty finding the next line
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SIGNS
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Fundus and optic nerves appear normal
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WORK-UP
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Pupils (typically normal) | EOMs (typically FROM) | Cover test | Color vision (Dyschromatopsia may be present) | Complete eye exam with dilation | Cranial nerve testing | Ptosis testing
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OCT of the optic nerve | OCT of the macula (Ganglion cell loss that correlates with visual field loss) | VEP
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Visual field threshold 30-2:
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Homonymous hemianopia: Very congruent. Lesion is on side opposite the homonymous hemianopia
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Paracentral homonymous scotomas: Very congruent. Lesion is at the tip of the occipital lobe on side opposite the homonymous hemianopia
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Macular sparing: A homonymous hemianopia that spares fixation by about 2-3 degrees. Lesion involves anywhere along the visual radiations on
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Bilateral central scotomas: Lesion involves both sides of the occipital lobe
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Ring scotoma: A small area of central vision remains. Lesion involves both sides of the occipital lobe
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Bilateral altitudinal defect: Altitudinal defects are usually inferior. Lesion involves both side of the occipital lobe
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Checkerboard field defects: Crossed quadrantanopia. Lesion is above the calcarine fissure on one side and below the calcarine fissure on the other side
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Octopus or Goldmann kinetic visual field:
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Temporal crescent sparing: Typically associated with incongruent homonymous hemianopia and sparing of the temporal field 60-90 degrees in one eye. Lesion involves the occipital lobe but spares the anterior portion of the occipital lobe. This field defect could be missed with a static visual field 30-2
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TREATMENT
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Refer to neuro-ophthalmologist/neurology for further evaluation and treatment
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After treatment, most visual recovery is noted in 1-4 months. Visual recovery after 6 months is unlikely. If visual symptoms are still present, patient should undergo vision rehabilitation and vision restorative training (glasses, prism, tint, etc)
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FOLLOW-UP
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Patient will likely be monitored by neurology/neuro-ophthalmology on a regular basis. Patient should be evaluated once underlying neurological etiology is in control or stable.
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Monitor every 3 months for the first year and then every 6-12 months
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ADDITIONAL LAB | TESTS
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MRI with and without contrast of the brain (concentration on the occipital lobe) | Neurological evaluation
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ETIOLOGY
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Occipital lesions are typically due to tumors, strokes, and trauma
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DIFFERENTIAL DX
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Temporal lobe lesion, Optic chiasm lesion, Parietal lobe lesion
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NOTES
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Cortical blindness: Loss of vision in both eyes due to lesions that involve both striate cortexes of the occipital lobes. The pupils and fundus are normal in both eyes. These patients may inform others that they see things even if they actually don’t (Anton’s syndrome). The most common cause is a stroke that involves posterior circulation, but can be seen with manipulation of the neck from chiropractors or carbon monoxide poisoning
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