Joint Shantou International Eye Center, Shantou University and The Chinese University of Hong Kong, Shantou, China.
Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
Transl Vis Sci Technol. 2020 Nov 13;9(12):20. doi: 10.1167/tvst.9.12.20. eCollection 2020 Nov.
To evaluate automated measurements of the foveal avascular zone (FAZ) using the Level Sets macro (LSM) in ImageJ as compared with the Cirrus optical coherence tomography angiography (OCTA) inbuilt algorithm and the Kanno-Saitama macro (KSM).
The eyes of healthy volunteers were scanned four times consecutively on the Zeiss Cirrus HD-OCT 5000 system. The FAZ metrics (area, perimeter, and circularity) were measured manually and automatically by the Cirrus inbuilt algorithm, the KSM, and the LSM. The accuracy and repeatability of all methods and agreement between automated and manual methods were evaluated.
The LSM segmented the FAZ with an average Dice coefficient of 0.9243. Compared with the KSM and the Cirrus inbuilt algorithm, the LSM outperformed them by 0.02 and 0.19, respectively, for Dice coefficients. Both the LSM (intraclass correlation coefficient [ICC] = 0.908; coefficient of variation [CoV] = 9.664%) and manual methods (ICC ≥ 0.921, CoV ≤ 8.727%) showed excellent repeatability for the FAZ area, whereas the other methods presented moderate to good repeatability (ICC ≤ 0.789, CoV ≥ 15.788%). Agreement with manual FAZ area measurement was excellent for both the LSM and KSM but not for the Cirrus inbuilt algorithm (LSM, ICC = 0.930; KSM, ICC = 0.928; Cirrus, ICC = 0.254).
The LSM exhibited greater accuracy and reliability compared to the KSM and inbuilt automated methods and may be an improved and accessible option for automated FAZ segmentation.
The LSM may be a suitable automated and customizable tool for FAZ quantification of Cirrus HD-OCT 5000 images, providing results comparable to those for manual measurement.
评估使用 ImageJ 中的 Level Sets 宏（LSM）自动测量中心凹无血管区（FAZ）与 Cirrus 光学相干断层扫描血管造影（OCTA）内置算法和 Kanno-Saitama 宏（KSM）的结果。
使用 Zeiss Cirrus HD-OCT 5000 系统连续对健康志愿者的眼睛进行四次扫描。手动和自动使用 Cirrus 内置算法、KSM 和 LSM 测量 FAZ 指标（面积、周长和圆度）。评估所有方法的准确性和可重复性以及自动方法与手动方法之间的一致性。
LSM 分割 FAZ 的平均 Dice 系数为 0.9243。与 KSM 和 Cirrus 内置算法相比，LSM 的 Dice 系数分别高出 0.02 和 0.19。LSM（组内相关系数[ICC]=0.908；变异系数[CoV]=9.664%）和手动方法（ICC≥0.921，CoV≤8.727%）均显示出 FAZ 面积的极好可重复性，而其他方法则显示出中等到良好的可重复性（ICC≤0.789，CoV≥15.788%）。LSM 和 KSM 与手动 FAZ 面积测量的一致性非常好，但 Cirrus 内置算法则不然（LSM，ICC=0.930；KSM，ICC=0.928；Cirrus，ICC=0.254）。
与 KSM 和内置自动方法相比，LSM 表现出更高的准确性和可靠性，可能是一种改进且易于使用的自动 FAZ 分割选择。
李欣怡
