Murtha Timothy, Stasheff Steven F
Harvard Medical School, Joslin Diabetes Center, Boston, MA, USA.
Neurol Clin. 2003 May;21(2):445-81. doi: 10.1016/s0733-8619(02)00108-1.
Visual perceptions seen with retinal and optic nerve disease may overlap with those resulting from retrochiasmal disorders. A few disorders typically present with distinctive perceptions, but the majority have less specific symptoms. Features include whether or not the visual phenomena are negative or positive, monocular or binocular, and the location and form of any deficits. Among negative phenomena, transient visual loss usually is the result of ischemic disease, but particular precipitants may suggest demyelination or photoreceptor degeneration. The pattern and location of visual field defects may help localize disorders to the level of the macula, papillomacular or other inner retina nerve fiber bundles, optic nerve, or chiasm. Altered brightness perception may point to optic nerve or photoreceptor disease. Decreased acuity is among the most common and least specific symptoms, but association with other symptoms may help to narrow the differential diagnosis. Dyschromatopsia points to either a photoreceptor or optic nerve pathologic condition (Table 7). Among positive phenomena, hallucinations resulting from anterior visual system disorders typically are unformed, although deafferentation of retrochiasmal pathways may produce formed hallucinations. The common "floaters" frequently are benign, but occasionally herald more concerning disorders. Various types of photopsias commonly occur with vitreal disorders or photoreceptor disorders. Macular disease typically leads to distortions of the central visual field, and other particular disorders lead to a host of characteristic distortions of color, form, or brightness. Careful attention to the ophthalmologic examination, visual fields, and subtle variance in symptomatology also help to distinguish among various disorders.
视网膜和视神经疾病所导致的视觉感知可能与视交叉后疾病所产生的视觉感知重叠。少数疾病通常呈现出独特的感知，但大多数疾病的症状不那么具有特异性。其特征包括视觉现象是阴性还是阳性、单眼还是双眼，以及任何缺陷的位置和形式。在阴性现象中，短暂性视力丧失通常是缺血性疾病的结果，但特定的诱发因素可能提示脱髓鞘或光感受器变性。视野缺损的模式和位置可能有助于将疾病定位到黄斑、乳头黄斑或其他视网膜内神经纤维束、视神经或视交叉水平。亮度感知改变可能提示视神经或光感受器疾病。视力下降是最常见且特异性最低的症状之一，但与其他症状相关联可能有助于缩小鉴别诊断范围。色觉异常提示光感受器或视神经病理状况（表7）。在阳性现象中，前视觉系统疾病导致的幻觉通常是不成形的，尽管视交叉后通路的传入神经阻滞可能产生成形的幻觉。常见的“飞蚊症”通常是良性的，但偶尔预示着更令人担忧的疾病。各种类型的闪光感常见于玻璃体疾病或光感受器疾病。黄斑疾病通常导致中心视野扭曲，而其他特定疾病则导致一系列颜色、形状或亮度的特征性扭曲。仔细关注眼科检查、视野以及症状学上的细微差异也有助于区分各种疾病。
