Ramachandran Rithambara, X Cai Cindy, Lee Dongwon, C Epstein Benjamin, Locke Kirsten G, G Birch David, C Hood Donald
Department of Psychology, Columbia University, New York, NY, USA.
Retina Foundation of Southwest, Dallas,TX, USA.
Transl Vis Sci Technol. 2016 May 17;5(3):6. doi: 10.1167/tvst.5.3.6. eCollection 2016 May.
We developed and evaluated a training procedure for marking the endpoints of the ellipsoid zone (EZ), also known as the inner segment/outer segment (IS/OS) border, on frequency domain optical coherence tomography (fdOCT) scans from patients with retinitis pigmentosa (RP).
A manual for marking EZ endpoints was developed and used to train 2 inexperienced graders. After training, an experienced grader and the 2 trained graders marked the endpoints on fdOCT horizontal line scans through the macula from 45 patients with RP. They marked the endpoints on these same scans again 1 month later.
Intragrader agreement was excellent. The intraclass correlation coefficient (ICC) was 0.99, the average difference of endpoint locations (19.6 μm) was close to 0 μm, and the 95% limits were between -284 and 323 μm, approximately ±1.1°. Intergrader agreement also was excellent. The ICC values were 0.98 (time 1) and 0.97 (time 2), the average difference among graders was close to zero, and the 95% limits of these differences was less than 350 μm, approximately 1.2°, for both test times.
While automated algorithms are becoming increasingly accurate, EZ endpoints still have to be verified manually and corrected when necessary. With training, the inter- and intragrader agreement of manually marked endpoints is excellent.
For clinical studies, the EZ endpoints can be marked by hand if a training procedure, including a manual, is used. The endpoint confidence intervals, well under ±2.0°, are considerably smaller than the 6° spacing for the typically used static visual field.
我们开发并评估了一种用于在视网膜色素变性（RP）患者的频域光学相干断层扫描（fdOCT）图像上标记椭圆体区（EZ）端点的训练程序，该区域也称为内节/外节（IS/OS）边界。
制定了一份标记EZ端点的手册，并用于培训2名经验不足的分级人员。培训后，一名经验丰富的分级人员和2名经过培训的分级人员在45例RP患者的fdOCT黄斑水平扫描线上标记端点。1个月后，他们在相同的扫描图像上再次标记端点。
分级人员内部一致性极佳。组内相关系数（ICC）为0.99，端点位置的平均差异（19.6μm）接近0μm，95%的限值在-284至323μm之间，约为±1.1°。分级人员之间的一致性也极佳。ICC值在第一次测试时为0.98，第二次测试时为0.97，分级人员之间的平均差异接近零，两次测试的差异95%限值均小于350μm，约为1.2°。
虽然自动算法越来越准确，但EZ端点仍需人工验证并在必要时进行校正。经过训练，人工标记端点的分级人员之间和分级人员内部一致性极佳。
对于临床研究，如果使用包括手册在内的训练程序，EZ端点可以手动标记。端点置信区间远低于±2.0°，比通常使用的静态视野的6°间距小得多。
