Suzuki Y
Department of Ophthalmology, Faculty of Medicine, University of Tokyo, Japan.
Surv Ophthalmol. 1995 May;39 Suppl 1:S57-65. doi: 10.1016/s0039-6257(05)80074-8.
A new method for the direct measurement of retinal vessel diameter was developed and the results were compared with those of two computer-assisted semiautomatic microdensitometric methods. The direct measurement method was based on automated detection of vessel edges by processing the one-dimensional retinal image obtained by a linear image sensor set in a fundus camera; results are obtained in real-time. Thirty-eight points on 36 vessels (15 points on arteries and 23 points on veins) of two normal volunteers (four eyes) were selected as the measurement points. Two observers measured the vessel diameters at these points and the interobserver variation of the direct method and the microdensitometric methods was compared. The coefficient of variation and the interobserver variation of the direct method for all measurements were 1.71 + 1.13% and 2.25 + 1.92%, respectively. There was no significant difference between the measured values for the two observers with the direct method (paired t-test, P > 0.05), and the interobserver variation of the direct method was smaller than those of the microdensitometric methods. This newly developed direct method for measurement of retinal vessel diameter not only avoids systematic errors that result from film development or the characteristics of the film, but also generates reproducible results in real-time and small interobserver variation.
开发了一种直接测量视网膜血管直径的新方法，并将结果与两种计算机辅助半自动显微密度测定法的结果进行了比较。直接测量方法基于通过处理由眼底相机中设置的线性图像传感器获得的一维视网膜图像来自动检测血管边缘；可实时获得结果。选择两名正常志愿者（四只眼睛）的36条血管上的38个点（动脉上15个点，静脉上23个点）作为测量点。两名观察者测量这些点处的血管直径，并比较直接法和显微密度测定法的观察者间差异。直接法所有测量的变异系数和观察者间差异分别为1.71 + 1.13%和2.25 + 1.92%。直接法两名观察者的测量值之间无显著差异（配对t检验，P > 0.05），且直接法的观察者间差异小于显微密度测定法。这种新开发的视网膜血管直径测量直接法不仅避免了由于显影或胶片特性导致的系统误差，还能实时产生可重复的结果且观察者间差异小。
