hemifield

hemifield

One half of the visual field, usually divided vertically through the fovea into the left or the right visual field. It occurs following transection of the optic chiasma. Hemifield neglect sometimes occurs following trauma to the posterior lobe of one hemisphere. See visual neglect.
References in periodicals archive ?
03 How many sectors does the Glaucoma Hemifield Test (GHT) compare between the upper and lower hemifields in the Humphrey Field Analyzer?
Left eye computerized visual field examination (24-2 Sita Standard, Humphrey field analyzer MODEL 740i, Carl Zeiss Meditec, Inc, Dublin, CA, USA) revealed an enlarged blind spot, a dense altitudinal superior scotoma and a slight diffuse reduction of sensitivity in the inferior hemifield. Right visual field was normal (Figure 3).
By manipulating the number of objects that the monkeys had to remember (1-3 objects in each visual hemifield), they observed that the increase in memory load produced modifications in the connectivity of the three regions examined.
Diagnosis criteria for JOAG were optic nerve head changes such as cup-to-disc (C/D) ratio [greater than or equal to]0.3 and localized neuroretinal rim defects, IOP [greater than or equal to]22 mmHg, glaucomatous changes of optic disc and retinal nerve fiber layer in OCT analysis, and visual field defects such as nasal step, Seidel, or arcuate scotoma, and abnormal glaucoma hemifield test in cooperative patients.
An early-stage glaucomatous visual field result was defined as mean deviation (MD) ≥ −6.00 dB and at least one of the following: (1) on a pattern deviation plot, there a cluster of three or more points in an expected location of the visual field depressed below the 5% level, at least one of which is depressed below the 1% level; (2) corrected pattern standard deviation/pattern standard deviation significant at P < 0.05; (3) glaucoma hemifield test 'outside normal limits.'[23]
(48) The right-dominant organization might be associated with the 'left field advantage' for face recognition; human subjects process face information faster when presented to the left hemifield than to the right hemifield.
For instance, the original "Organic Brain Syndrome" classification, as outlined in the first Diagnostic and Statistical Manual (DSM) of the American Psychiatric Association, was that objective neurological deficits had to be obviously expressed as some abnormal reflex, motor (hemiplegia), sensory (visual field defect), perceptual (hemifield neglect), sensory-perceptual (graphomotor impairment), and/or language (aphasia) indicator.
Dataset A corresponds to the activity while the subject attends to the left visual hemifield and the target appears at the same location in the left visual hemifield.
Ptosis may cause a variety of symptoms such as blurred vision, tearing/epiphora, or an impaired upper visual hemifield, which often results in an abnormal head posture of the patient [1].
When a cluster of three or more points in a pattern deviation plot within a single hemifield with a P value < 5% was observed, it was defined as an abnormal visual field.
Visual field loss was defined as glaucoma hemifield test result outside the normal limits and three points abnormal at the 5% level in one hemifield on the pattern deviation plot of a Humphrey Visual Field Analyzer.
The average superior hemifield retinal sensitivity of visual field analysis is 24.04 [+ or -] 1.603 dB in mild glaucoma group, 19.53 [+ or -] 3.565 dB in moderate glaucoma group and 3.69 [+ or -] 4.424 dB in severe glaucoma group.