Good G W, Quinn T G
J Am Optom Assoc. 1984 Dec;55(12):889-93.
Cup/disk (C/D) ratio estimation is frequently used to evaluate cupping within the optic nerve head. Two components are involved in the determination of this value: (1) the cup and disk margin determination, and subsequently (2) the magnitude estimation of the cup size relative to the disk size. This study investigated the magnitude estimation component by asking fourth year optometry students to estimate C/D ratios on optic nerve head photographs and drawings. The importance of the magnitude estimation was demonstrated by the high degree of variability among subjects on the nerve head drawings upon which cup and disk margins were presented unambiguously. A subsequent survey of faculty clinicians indicated a large percentage of practitioners (41%) have no method they consciously use to help determine their C/D ratio estimate. A specific method is presented which allows clinicians to simply and logically deduce this magnitude estimation.
杯盘比（C/D）估计常用于评估视神经乳头的杯状凹陷情况。该值的确定涉及两个部分：（1）杯盘边缘的确定，以及（2）杯大小相对于盘大小的数值估计。本研究通过让四年级验光专业学生对视神经乳头照片和绘图估计C/D比，来调查数值估计部分。在明确呈现杯盘边缘的神经乳头绘图上，受试者之间存在高度变异性，这证明了数值估计的重要性。随后对临床教师的一项调查表明，很大比例（41%）的从业者没有他们自觉使用的方法来帮助确定其C/D比估计值。本文提出了一种具体方法，使临床医生能够简单且合乎逻辑地推断出这种数值估计。
