Odell Daniel, Dubis Adam M, Lever Jackson F, Stepien Kimberly E, Carroll Joseph
Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
J Ophthalmol. 2011;2011:692574. doi: 10.1155/2011/692574. Epub 2011 Aug 17.
SD-OCT has become an essential tool for evaluating macular pathology; however several aspects of data collection and analysis affect the accuracy of retinal thickness measurements. Here we evaluated sampling density, scan centering, and axial length compensation as factors affecting the accuracy of macular thickness maps. Forty-three patients with various retinal pathologies and 113 normal subjects were imaged using Cirrus HD-OCT. Reduced B-scan density was associated with increased interpolation error in ETDRS macular thickness plots. Correcting for individual differences in axial length revealed modest errors in retinal thickness maps, while more pronounced errors were observed when the ETDRS plot was not positioned at the center of the fovea (which can occur as a result of errant fixation). Cumulative error can exceed hundreds of microns, even under "ideal observer" conditions. This preventable error is particularly relevant when attempting to compare macular thickness maps to normative databases or measuring the area or volume of retinal features.
光谱域光学相干断层扫描（SD-OCT）已成为评估黄斑病变的重要工具；然而，数据采集和分析的几个方面会影响视网膜厚度测量的准确性。在此，我们评估了采样密度、扫描中心定位和眼轴长度补偿作为影响黄斑厚度图准确性的因素。使用Cirrus HD-OCT对43例患有各种视网膜病变的患者和113名正常受试者进行了成像。B扫描密度降低与早期糖尿病性视网膜病变研究（ETDRS）黄斑厚度图中的插值误差增加有关。校正眼轴长度的个体差异显示视网膜厚度图中存在适度误差，而当ETDRS图未位于黄斑中心凹时（这可能由于注视错误而发生），则观察到更明显的误差。即使在“理想观察者”条件下，累积误差也可能超过数百微米。当试图将黄斑厚度图与标准数据库进行比较或测量视网膜特征的面积或体积时，这种可预防的误差尤为重要。
