Background
Visual field testing is a crucial component of the neurologic, and more specifically the ophthalmologic, examination. A lesion or disruption may occur anywhere in the pathway from the striate cortex of the occipital lobe to the retina, causing a specific visual field defect. Identification of that deficit leads to an appropriate workup and ultimate diagnosis. Visual field testing can be performed by the non-ophthalmologist proficiently and quickly as part of the bedside examination. Detailed plotting devices used by ophthalmologists also exist to more precisely locate the field deficit (see the image below). [1, 2, 3, 4, 5, 6, 7]
Indications
Indications for visual field testing include visual field deficits, vision loss, headache, and neurologic deficits.
Patients with the following medical conditions should undergo regular visual field testing by an ophthalmologist to monitor progression:
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Glaucoma
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Multiple sclerosis and neuromyelitis optica spectrum disorders (NMOSD)
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Thyroid eye disease (TED) and other orbital tissue diseases
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Pituitary gland disorders
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Central nervous system disorders (eg, tumors, Idiopathic intracranial hypertension IIH)
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Stroke
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Uveitis
Patient Education
It is important that the treating physician explains to patients why perimetry is important in treatment decisions. For glaucoma patients, for instance, the doctor should explain that the visual field is the indicator of the quality of life as well as that it determines how the patient sees now and in the future.
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Schematic representation of visual system.
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Normal visual field of the right eye. Note the black circle on the upper right representing the optic nerve (blind spot).
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A patient's visual field test of the left eye showing a typical glaucoma defect.
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Visual field test of a patient showing right homonymous hemianopsia from a contralateral neurological lesion.
