Blamires T L, Reeves B C
Department of Ophthalmology, Kettering General Hospital, Northamptonshire, United Kingdom.
Optom Vis Sci. 1996 Sep;73(9):572-8. doi: 10.1097/00006324-199609000-00002.
Patients with chiasmal lesions frequently suffer loss of vision, but some may be visually asymptomatic and have little, if any, visual field loss. This study addressed two questions about the nature of such loss: (1) which tests are best able to detect visual loss and (2) what is the relation between the size of a lesion and the degree and type of visual loss.
Visual acuity (VA), Goldmann perimetry, pattern evoked potentials, contrast sensitivity (CS), and color vision (CV) were assessed, in addition to a full ophthalmologic examination. Thirty-five patients were recruited from neurology, endocrinology, and ophthalmology departments; 31 had pituitary tumors and 4 had tumors of other origin (1 secondary) close to the chiasm. For analysis, patients were classified (1) according to whether they had visual symptoms on presentation and (2) according to lesion size.
Seventeen patients had visual symptoms; all had visual field defects and all but one had two or more additional abnormal test results. Of the 18 visually asymptomatic patients, 12 had visual field defects and 14 had at least 2 abnormal test results; 7 had tumors with less than 5 mm of suprasellar extension, of whom 5 had field loss or at least 2 abnormal test results. CS was abnormal most often (85% of patients), followed by Goldmann perimetry (80%), visual evoked potentials (VEPs) (57%), CV (49%), and VA (26%).
Our results support previous reports that asymptomatic patients and those with intrasellar tumors or only small amounts of suprasellar extension may have demonstrable visual dysfunction. Perimetry did not appear to be significantly worse than other more recently developed tests, which have often been regarded as being more sensitive, for detecting vision loss. However, VA and clinical observation of pupil reactions had poor sensitivity.
视交叉病变患者常出现视力丧失，但部分患者可能无视觉症状，几乎没有视野缺损（即便有也很轻微）。本研究针对此类视力丧失的性质探讨了两个问题：（1）哪些检查最能检测出视力丧失；（2）病变大小与视力丧失的程度及类型之间有何关系。
除了进行全面的眼科检查外，还评估了视力（VA）、Goldmann视野检查、图形诱发电位、对比敏感度（CS）和色觉（CV）。从神经科、内分泌科和眼科招募了35名患者；其中31例患有垂体肿瘤，4例患有其他起源（1例为继发性）且靠近视交叉的肿瘤。为进行分析，将患者按以下方式分类：（1）根据就诊时是否有视觉症状；（2）根据病变大小。
17例患者有视觉症状；所有患者均有视野缺损，除1例患者外，其余患者均有两项或更多其他异常检查结果。在18例无视觉症状的患者中，12例有视野缺损，14例至少有两项异常检查结果；7例患者的肿瘤鞍上延伸小于5mm，其中5例有视野缺损或至少两项异常检查结果。CS异常最为常见（85%的患者），其次是Goldmann视野检查（80%）、视觉诱发电位（VEP）（57%）、CV（49%）和VA（26%）。
我们的结果支持先前的报道，即无症状患者以及患有鞍内肿瘤或仅少量鞍上延伸的患者可能存在可证实的视觉功能障碍。对于检测视力丧失，视野检查似乎并不比其他近来常被认为更敏感的检查明显差。然而，VA和瞳孔反应的临床观察敏感性较差。
