Hemianopsia

hemianopsia

[‚he·mē·ə′näp·sē·ə] (medicine) Bilateral or unilateral blindness in one-half of the field of vision.

Hemianopsia

loss of half of the field of vision; half blindness.

Hemianopsia is described as either multilateral, which is characterized by loss of either the outer or the inner halves of the field of vision, or unilateral (homonymous), in which the same halves of the field of vision (whether right or left) are lost. Hemianopsia occurs with cerebal hemorrhage, cranial injuries, or brain tumors. If the brain tissue is not entirely destroyed, hemianopsia is reversible. The lost field of vision is usually blind to all types of visual sensations, although sometimes perception of the shape of an object, for example, is lost, while perception of color, light, and movement in the same field of vision is preserved. Treatment involves elimination of the primary cause of the hemianopsia.

hemianopsia

hemianopia

[hem″e-ah-no´pe-ah] defective vision or blindness" >blindness in half of the visual field; usually applied to bilateral defects caused by a single lesion. adj., adj hemianop´ic, hemianop´tic.Patient Care. Visual field deficit on one side often occurs as a result of stroke syndrome. Patients with this problem are unable to perceive objects to the side of the visual midline. The visual loss is contralateral, i.e., it is on the side opposite the brain lesion. To facilitate self care, commonly used articles such as the water pitcher, meal tray, and call bell are placed on the unaffected side. The patient should be approached from and communicated with while standing or sitting on the side in which vision is best. When in visual contact with the patient, caregivers should move slowly toward and past the visual boundary to stimulate scanning to the affected side. Auditory and visual stimulation on the affected side can help improve and maintain residual sight on that side.

Visual field defects associated with hemianopia. From Polaski and Tatro, 1996.homonymous hemianopia hemianopia affecting the right halves or the left halves of the visual fields of both eyes. The patient must turn the head from side to side to compensate for the defect. Often it is due not to any pathology in the eye itself but to damage to the optic tract or occipital lobe.

hem·i·a·no·pi·a

(hem'ē-ă-nō'pē-ă), Loss of vision for one half of the visual field of one or both eyes. Synonym(s): hemianopsia

hemianopia

Loss of vision in one half of the visual field of one eye (unilateral hemianopia) or of both eyes (bilateral hemianopia) (Fig. H1). Syn. hemianopsia. See quadrantanopia; hemianopic pupillary reflex.
absolute hemianopia Hemianopia in which the affected part of the retina is totally blind to light, form and colour.
altitudinal hemianopia Hemianopia in either the upper or lower half of the visual field. A common cause is anterior ischaemic optic neuropathy.
binasal hemianopia Hemianopia in the nasal halves of the visual fields of both eyes.
bitemporal hemianopia Hemianopia in the temporal halves of the visual fields of both eyes.
congruous hemianopia Hemianopia in which the defects in the two visual fields are identical. A common cause is a lesion in the posterior optic radiations.
heteronymous hemianopia A loss of vision in either both nasal halves (binasal hemianopia) or both temporal halves of the visual field (bitemporal hemianopia). A common cause of the latter is a lesion in the optic chiasma.
homonymous hemianopia A loss of vision in the nasal half of the visual field of one eye and the temporal half of the visual field of the other eye. Left homonymous hemianopia is a loss of vision in the temporal half of the visual field of the left eye and the nasal half of the visual field of the right eye. Right homonymous hemianopia is a loss of vision in the temporal half of the visual field of the right eye and the nasal half of the visual field of the left eye. Common causes are occlusion of the posterior cerebral artery (stroke), trauma and tumours. See macular sparing.
incongruous hemianopia Hemianopia in which the defects in the two affected visual fields differ in one or more ways. A common cause is a lesion of the optic tract.
quadrantic hemianopia See quadrantanopia.
relative hemianopia Hemianopia involving a loss of form and colour but not of light.
hemianopia spectacles See hemia-nopic spectacles.

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Fig. H1 Complete, bitemporal hemianopia due to a large pituitary tumour compressing the optic chiasma

hemianopsia

Hemianopsia

hemianopsia

Hemianopsia

hemianopsia

hemianopia

hem·i·a·no·pi·a

hemianopia

hemianopsia

Synonyms for hemianopsia

noun blindness in one half of the visual field of one or both eyes

Synonyms

Related Words