目的:描述新的对比敏感度及色觉检查的原理及其临床应用.方法:对比敏感度用SLCT来评估.SLCT是由几行大小不变(20/25),但对比度逐渐降低的字母组成的对比敏感度表.色觉以锥细胞的对比敏感度来评估,这是一种视屏测试方法,每一个字母都代表三种视锥细胞中的一种类型(红、绿或蓝),对比度逐渐降低,分别确定分辨的阈值.测试对象分别为正常受试者以及有眼部疾病的患者.结果:SLCT在检查微小的离焦量以及早期眼部疾病方面比传统的检查具有更大的优势.锥细胞对比敏感度测试比传统的色觉检查敏感性高,不仅可以揭示遗传性色觉异常的类型及其严重程度,而且可以发现不同疾病造成的敏感度的下降.结论:这些新的方法拓展了视觉评估领域,揭示了人眼分辨力的微小变化,提示了遗传性、获得色觉异常眼病的类型和严重程度.%Objective:To describe the theoretical basis and clinical application of new methods of contrast sensitivity and color vision assessment.Methods:Contrast sensitivity was assessed with the small letter contrast test(SLCT),a chart comprised of letters of constant size(20/25) which decrease in contrast,by row,from a clearly visible level at the top,to threshold levels at the bottom. Color vision was assessed with cone contrast sensitivity,a computer-based test in which letters visible to a single cone type(red,green or blue),are presented in decreasing steps of cone contrast to determine the threshold for letter recognition. The SLCT and cone contrast sensitivity was assessed in normal subjects and in patients with eye disease.Results:The SLCT was more sensitive than standard tests for detection of small degrees of defocus,as well as early stages of eye disease. Cone contrast sensitivity proved more sensitive than standard color tests,revealing both type and severity of hereditary color deficiency,and sensitivity decrements acquired early in the course of various diseases.Conclusion:These new approaches extend the realm of vision assessment,revealing subtle changes in visual resolution,as well as type and severity of hereditary and acquired color deficiency.
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