macular avoidance
Introduction
Introduction Macular avoidance refers to the phenomenon that the central fixation zone functions in the blunt and blind-wide field of view during visual field examination. The appearance of this phenomenon is seen in lesions or lesions in the posterior or visual cortical area of the radioactivity.
Cause
Cause
The appearance of this phenomenon is seen in lesions or lesions in the posterior or visual cortical area of the radioactivity. The following explanations are given for the mechanism of macular avoidance:
(1), the macular area is dominated by the cerebral cortex on both sides, and the corpus callosum of the corpus callosum leads to the ventral side of the bilateral radioactive fibers, which may be related to the bilateral macular bundles. This is a popular interpretation.
(2), because the macular fiber is widely distributed in the occipital cortex, usually a lesion is difficult to completely destroy the area of the distribution, it can be a macular avoidance phenomenon.
(3), because the macular fiber finally occipital cortex, the Department has blood circulation from 2-3 blood sources, when the lesion only blocks a blood circulation, the macular fiber function is not damaged.
Examine
an examination
Related inspection
Ophthalmology examination ophthalmoscopy eye function examination fundus examination
When all of the side-view radiation is damaged, the bilateral visual field is unilaterally blunt, and the blunt-side pupillary photoreaction still exists, and the central portion of the visual field is often preserved.
(1) The macular area is dominated by the cerebral cortex on both sides. The corpus callosum in the tail of the corpus callosum leads to the ventral side of the bilateral radioactive fibers, which may be related to the bilateral macular bundles. This is a popular interpretation.
(2) Because the macular fiber is widely distributed in the occipital cortex, it is usually difficult for a lesion to completely destroy the distributed area, so it may be a macular avoidance phenomenon.
(3) Since the macular fiber finally has the occipital cortex, there is a blood circulation supply from 2-3 blood sources, and the macular fiber function is not impaired when the lesion only blocks one blood circulation.
Diagnosis
Differential diagnosis
Differential diagnosis of macular avoidance:
1. Impaired occipital lobe is a symptom manifested by diseases such as occipital lobe tumor, occipital lobe cerebral infarction. The occipital leaf is damaged. Mainly manifested as visual obstacles. In the case of unilateral occipital lobe lesions, the central visual field often stays, which is called the phenomenon of macular avoidance.
2. The posterior cerebral artery occlusion is characterized by contralateral unilateral bluntness of the lesion, with macular avoidance and cortical blindness or quadrant blindness. The central blush light reflection exists, is quadrant hemianopia, and has no self-conscious symptoms. The latter has a visual center of vision preservation, which is a phenomenon of macular avoidance. When all of the side-view radiation is damaged, the bilateral visual field is unilaterally blunt, and the blunt-side pupillary photoreaction still exists, and the central portion of the visual field is often preserved.
