quadrant hemianopia
Introduction
Introduction Quadrant hemianopia, also known as quadrant defect, that is, visual field defect occupying a quadrant, is more common in visual path damage above the optic chiasm. The hemianopia caused by visual pathological lesions often contributes to the localization diagnosis of neuropathy. When the optic chiasm is oppressed by the tumor, it often causes typical bilateral hemianopia.
Cause
Cause
Partial hemianism: Medical terminology refers to the partial diagnosis of a part of the visual field. The hemianopia caused by visual pathological lesions often contributes to the localization diagnosis of neuropathy. When the optic chiasm is oppressed by the tumor, it often causes typical bilateral hemianopia. Some ophthalmic diseases can also cause hemianopia-type visual field defects, such as nasal visual field defects in advanced glaucoma, blunt-type visual field defects in retinal vascular occlusion, and visual field defects in the opposite direction when the retina is partially detached.
Examine
an examination
Related inspection
Ultrasound examination of the eyeball and eyelid and CT examination of the temporal region
There are two types of visual field defects:
1 sacral hemianopia: If the bilateral nerve conduction to the nasal retinal vision caused by tumor compression is involved, bilateral stimuli may not be accepted and bilateral sacral hemianopia may occur. When the tumor grows up, the side loses its visual function due to the weight on one side, and the other side is blind, and the other side is unilaterally blind.
2 omnidirectional hemianopia: damage to the pathway after the optic tract or the lateral geniculate body can produce a visual field defect on one side of the nasal side and the other side of the iliac crest, which is called co-directional hemianopia.
The visual beam is different from the central hemianopia. The former is accompanied by the disappearance of light reflection, and the latter has light reflection. The former is blunt and complete, while the latter is more incomplete and quadrant hemian; the former patient's subjective sensory symptoms are more significant than the latter. No self-conscious symptoms; the latter's visual field center of vision is preserved, showing macular avoidance.
Diagnosis
Differential diagnosis
Normal tension glaucoma is a special glaucoma. Intraocular pressure is not the main pathogenic factor, but it is closely related to other systemic diseases. The pathogenesis of this disease is still unclear. However, as long as it is glaucoma, its optic atrophy is specific, unlike optic atrophy caused by other diseases, which is mainly distinguished from the visual field. There is a strong regularity in the visual field defect of glaucoma. The paracentral dark spot, the nasal dark spot and the temporal side visual field defect often appear in the early stage; the bow dark spot and the quadrant visual field defect usually appear in the middle stage; Island and tubular view. The visual field defects caused by other eye diseases or intracranial tumors do not have such regularity, and are generally easier to distinguish. In addition, the microscopic feature of optic atrophy is that the optic nerve fiber layer becomes thinner, and the macroscopic feature is the visual field defect.
