Bracher D, Dozzi M, Lotmar W
Albrecht Von Graefes Arch Klin Exp Ophthalmol. 1979 Jul 2;211(1):35-48. doi: 10.1007/BF00414652.
Many factors play a role in determining the width of retinal vessels, based on fundus photographs. We have tried to estimate their influence by comparing experimentally six different measuring methods, taking into account film and developer, intra- and interindividual reproducibility of results under short- and long-term conditions, and training in measuring technique. Our method of choice was tenfold projection of the negatives on a fine-grained wax layer screen and use of a very narrow marker line to be aligned with the vessel borders. Width determinations on pictures of good definition, yet low contrast, repeated by a trained observer on consecutive days, lay with a 95% probability within an interval of about 9 micron on the retina. The width so determined is, of course, relative and only a rough approximation to the absolute width, because of photographic bias, interobserver difference, and uncertainly of the refractive power of the eye. The method appears to be especially suitable for the study of intraindividual variations; however, because of photographic bias, conclusions should be drawn only when based on several pictures.
基于眼底照片，许多因素在决定视网膜血管宽度方面发挥作用。我们通过实验比较六种不同测量方法来评估它们的影响，同时考虑胶片和显影剂、短期和长期条件下结果的个体内和个体间再现性以及测量技术培训。我们选择的方法是将底片在细颗粒蜡层屏幕上进行十倍投影，并使用一条非常窄的标记线与血管边界对齐。由经过训练的观察者在连续几天对清晰度良好但对比度低的图片进行血管宽度测定，在视网膜上95%的概率落在约9微米的区间内。当然，由于摄影偏差、观察者间差异以及眼睛屈光力的不确定性，如此确定的宽度是相对的，只是绝对宽度的粗略近似值。该方法似乎特别适合研究个体内差异；然而，由于摄影偏差，只有基于多张图片时才能得出结论。
