Decibel scale humphrey visual filed
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If it is homonymous, is the defect complete or incomplete?ħ. If it respects the vertical meridian, is the defect bitemporal or homonymous?Ħ. If binocular, does the defect respect the vertical meridian?ĥ. Does the visual field defect involve one eye or two eyes?Ĥ. Is the test reliable (as indicated by the technician for Goldmann visual fields and by the reliability parameters for automated perimetry)?ģ. Possibly a decreased visual acuity that is equal in each eye (unless additional pathology is present anterior to chiasm).ġ. Thus the nasal visual field extends to 60% of the horizon, whereas the temporal field extends to a further 30°-40°Ģ. The most nasal retinal fibers have unpaired cortical representation, which is situated in the most anterior part of the contralateral parieto-occipital sulcus. Retrochiasmal lesions normally cause homonymous visual field defects the only exception is the ‘temporal crescent’ or ‘half moon syndrome’, caused by a lesion in the anterior part of the contralateral parieto-occipital sulcus. The VF defect is a homonymous hemianopia with sparing of the temporal crescent on the same side as the hemianopia. An embolic infarction of either a distal MCA or PCA branch can result in exclusive ischemia of the tip of the occipital lobe, thereby producing only a small homonymous hemianopia if there is inadequate collateral circulation. If the middle cerebral artery is patent when the PCA is occluded, this focal area of the occipital lobe may be spared.Ī contralateral homonymous hemianopia that is small and centrally located. The tip of the occipital lobe, where the macular central homonymous hemifields are represented, often has a dual blood supply from terminal branches of the posterior cerebral artery and of the middle cerebral artery. Occlusion of the PCA often results homonymous hemianopia of the contralateral visual field with macular sparing. Deep lesions of the parietal lobe often impair optokinetic nystagmus when stimuli are moved in the direction of the damaged parietal lobe. A homonymous hemianopsia denser inferiorly (opposite of pie in the sky)Ģ. A Homonymous hemianopia denser superiorly (“pie in the sky”)ġ. Mostly temporal pallor of the left optic nerve from atrophy of the temporal retina in the left eye.ġ. Bowtie atrophy of the right optic nerve from atrophy of fibers supplying the nasal half of the macula and nasal retina of the right eye.Ĥ. A right RAPD (contralateral to lesion) because more fibers (53%) in the optic tract come from the opposite eye’s nasal retina, having crossed in the chiasm.ģ. A right homonymous hemianopia (contralateral to lesion)Ģ. The lesion is at the most posterior portion of the optic nerve ipsilateral to the central scotoma at its “junction” with the chiasm.ġ. Wilbrand’s knee is composed of fibers originating in the inferonasal retina which after traversing via the optic nerve and crossing in the chiasm go anteriorly into the contralateral optic nerve up to 4 mm before passing posteriorly to the optic tract.Ī central scotoma in the eye ipsilateral to the lesion & a superotemporal defect in the fellow eye. Junctional scotoma, Bitemporal defects, Homonymous hemianopia defects (w/wo macular sparing, spared temporal crescent)Ī junctional scotoma. In interpreting a visual field test, what questions should be asked?Ĭentral, Cecocentral, Paracentral, Arcuate/Sector, Nasal Step, Altitudinal, Enlarged blind spots, Temporal Crescent Defect. What are the findings of bilateral occipital lobe lesions?ġ5.
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What field defect results when a stroke only affects the anterior portion of the occipital lobe?ġ4. What field defect results when a stroke affects the occipital lobe but spares the anterior portion of the occipital lobe?ġ3. What field defects results from ischemia limited to of the tip of an occipital lobe?ġ2. What are the findings of an occlusion of the posterior cerebral artery?ġ1. What are the findings of a parietal lobe lesion?ġ0. What are the findings of a temporal lobe lesion?ĩ. What are the findings of a left optic tract lesion?Ĩ. Where is the lesion of a junctional scotoma?ħ. What is the visual field defect of a junctional scotoma?Ħ. A lesion of Wilbrand’s Knee results in what visual field defect?ĥ. What are the bilateral VF defect patterns?Ĥ. What are the monocular VF defect patterns?ģ. What values indicate an unreliable Humphrey Visual Field?Ģ.