Assad A, Caprioli J
Yale University School of Medicine, Department of Ophthalmology and Visual Science, New Haven, CT 06510.
Graefes Arch Clin Exp Ophthalmol. 1992;230(5):432-6. doi: 10.1007/BF00175928.
We developed a computer-based technique to quantify optic nerve head pallor from videographically acquired digitized optic nerve images and tested the ability of pallor measurements to discriminate between normal eyes and eyes with early glaucoma. Corresponding pixel values from images obtained under 540 nm (green) and 640 nm (red) light with a videographic fundus camera were used to quantify optic nerve head pallor. A pallor density histogram was calculated for each eye, and contained values between 0 (red) to 1 (white). A measure of the distribution width of the histogram provided pallor measurements standardized to the measurements of the large veins of the disc. A database of one eye each of 44 normal controls and 70 patients with early open angle glaucoma was used to test the measurements for diagnostic sensitivity and specificity. These standardized pallor measurements did not perform better than absolute pallor measurements to discriminate between normal and glaucomatous eyes. The sensitivity and specificity of standardized pallor measurements (49% and 57%, respectively, for this database) were not as good as those for stereoscopic measurements of disc rim area in the same database (70% and 73%). Pallor measurements of this type do not appear to be sensitive or specific indicators of early glaucoma.
我们开发了一种基于计算机的技术，用于从视频采集的数字化视神经图像中量化视神经乳头苍白，并测试苍白测量值区分正常眼和早期青光眼眼的能力。使用眼底摄像机在540纳米（绿色）和640纳米（红色）光下获得的图像中的相应像素值来量化视神经乳头苍白。为每只眼睛计算一个苍白密度直方图，其值在0（红色）到1（白色）之间。直方图分布宽度的测量提供了根据视盘大静脉测量进行标准化的苍白测量值。使用44名正常对照者和70名早期开角型青光眼患者的单眼数据库来测试测量的诊断敏感性和特异性。这些标准化的苍白测量值在区分正常眼和青光眼眼方面并不比绝对苍白测量值表现更好。标准化苍白测量值（该数据库中分别为49%和57%）的敏感性和特异性不如同一数据库中视盘边缘区域立体测量值的敏感性和特异性（70%和73%）。这种类型的苍白测量似乎不是早期青光眼的敏感或特异性指标。
