hemianopia


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hemianopia

 [hem″e-ah-no´pe-ah]
defective vision or 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

Hemianospia Neurology Loss of one half of the field of vision

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.

hemianopia

Loss of half of the field of vision of one or both eyes. Hemianopia usually affects corresponding halves of the visual fields of both eyes as it is usually due to damage to the optical nerve tracts behind the eyes that contain fibres from both eyes. In homonymous hemianopia there is loss of corresponding halves of the field of each eye. In bitemporal hemianopia both outer halves are lost. Hemianopia is a common symptom of STROKE or pituitary gland tumour.

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.
Fig. H1 Complete, bitemporal hemianopia due to a large pituitary tumour compressing the optic chiasmaenlarge picture
Fig. H1 Complete, bitemporal hemianopia due to a large pituitary tumour compressing the optic chiasma
References in periodicals archive ?
In at least 22 states and many other countries, people with hemianopia are prohibited from driving because they do not meet the visual field requirements for licensure.
Exclusion criteria were Parkinson's disease, multiple sclerosis, Alzheimer's disease, hemiparesis, ocular or neurological conditions resulting in visual field defects (other than hemianopia or quadrantanopia), and lateral spatial neglect as defined by the Stars test [14].
The most frequent neurological deficit in occipital lobe AVM is homonymous hemianopia occurring in 39-57% of patients3,5,6.
Although Hemianopia is not total blindness, it is a very disabling condition.
In the present study, among the non-epileptic manifestations, headache with or without vomiting (10, 19.23%) was the most common presentation followed by hemiparesis 8 (15.38%), either of right or left, homonymous hemianopia 6 (11.54%), and hemichorea 6 (11.54%) in cases of single ring enhancing computed tomography lesion [Table-3].
She described seeing a bright spinning beach ball in her right visual field intermittently, and physical exam showed constant right homonymous hemianopia. These symptoms were similar to those associated with a previous episode of clustered seizures that happened four years ago, at which point she was prescribed an antiepileptic agent, Levetiracetam.
One patient (MN) was diagnosed with left-sided hemianopia. Perseverative behaviors in spatial cancellation tasks were not observed in all patients [10].
right homonymous hemianopia with bi- temporal field defects.
Brain injury may result in reduced visual acuity, loss of a visual field (such as the nasal or temporal field and quandranopia and hemianopia either in the superior or inferior field), and binocular vision disorders.
Six different Wylie Cards have now been launched, illustrating the effects of the six most common eye conditions - macular degeneration, cataracts, glaucoma, diabetic retinopathy, hemianopia and retinitis pigmentosa.
Hemianopia, old age, somatosensory deficiencies and side of stroke are possible negative predictors [9].