Inter- and intraobserver variation in the analysis of optic disc images: comparison of the Heidelberg retina tomograph and computer assisted planimetry
Inter- and intraobserver variation in the analysis of optic disc images: comparison of the Heidelberg retina tomograph and computer assisted planimetry
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DOI：
10.1136/bjo.83.6.664
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发表时间：
1999-06-01
影响因子：
4.1
通讯作者：
Hitchings, RA
中科院分区：
文献类型：
--
作者：
Garway-Heath, DF;Poinoosawmy, D;Hitchings, RA
AIMS-成像和测量技术的发展为视盘特征的测量带来了更大的客观性，因此观察者之间的一致性更好。这项研究的目的是量化和比较使用两种测量设备的观察者之间的差异。方法-将30名受试者30只眼的视盘照片和海德堡视网膜断层扫描仪(HRT)的图像提交给6名观察者进行分析，并在5种不同的情况下提供给1名观察者。观察者之间的一致性是通过将每个观察者的分析结果与其他五个观察者的中位数结果进行比较来研究的，并表示为观察者与中位数之间的平均差异和标准差。结果：对于平面测量学，观察者之间的一致性依赖于观察者的经验，而对于HRT，它是独立的。视盘面积的一致性为4.0%~7.2%(平面测量法)和3.3%~6.0%(HRT)，神经视网膜缘区的一致性为10.8%~21.0%(平面测量法)和5.2%~9.6%(HRT)。视盘区的平均变异系数为8.1%(平面测量)和4.4%(HRT)，视网膜边缘区的平均变异系数为16.3%(平面测量)和8.1%(HRT)，边缘体积的平均变异系数为16.3%，参考高度为9.1%。软件版本1.11参考平面的HRT变异性大于版本1.10。视盘区的观察者内变异系数分别为1.5%(平面法)和2.4%(HRT)，神经视网膜缘区的观察者内变异系数分别为4.0%(平面法)和4.5%(HRT)。然而，可能具有临床意义的变异水平仍然存在于取决于椎间盘边缘的主观绘制的变量中。
Aims-The development of imaging and measurement techniques has brought the prospect of greater objectivity in the measurement of optic disc features, and therefore better agreement between observers. The purpose of this study was to quantify and compare the variation between observers using two measurement devices.Methods-Optic disc photographs and images from the Heidelberg retina tomograph (HRT) of 30 eyes of 30 subjects were presented to six observers for analysis, and to one observer on five separate occasions. Agreement between observers was studied by comparing the analysis of each observer with the median result of the other five, and expressed as the mean difference and standard deviation of differences between the observer and the median. Inter- and intraobserver variation was calculated as a coefficient of variation (mean SD/mean x 100).Results-For planimetry, agreement between observers was dependent on observer experience, for the HRT it was independent. Agreement between observers (SD of differences as a percentage of the median) for optic disc area was 4.0% to 7.2% (planimetry) and 3.3% to 6.0% (HRT), for neuroretinal rim area it was 10.8% to 21.0% (planimetry) and 5.2% to 9.6% (HRT). The mean interobserver coefficient of variation for optic disc area was 8.1% (planimetry) and 4.4% (HRT), for neuroretinal rim area it was 16.3% (planimetry) and 8.1% (HRT), and (HRT only) for rim volume was 16.3%, and reference height 9.1%. HRT variability was greater for the software version 1.11 reference plane than for version 1.10. The intraobserver coefficient of variation for optic disc area was 1.5% (planimetry) and 2.4% (HRT), for neuroretinal rim area it was 4.0% (planimetry) and 4.5% (HRT).Conclusions-Variation between observers is greatly reduced by the HRT when compared with planimetry. However, levels of variation, which may be clinically significant, remain for variables that depend on the subjective drawing of the disc margin.