Lee Jong Ha, Lee Min Woo, Baek Seung Kook, Lee Young Hoon
Department of Ophthalmology, Konyang University College of Medicine, Daejeon, Korea.
Korean J Ophthalmol. 2020 Apr;34(2):113-120. doi: 10.3341/kjo.2019.0105.
To analyze the repeatability of manual measurement of foveal avascular zone (FAZ) area in an optical coherence tomography angiography (OCTA) image in high myopia.
This study comprised patients with high myopia and controls. Two consecutive FAZ areas of the superficial and deep capillary plexus were obtained using OCTA. The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were assessed, and univariate and multivariate generalized linear mixed models were conducted to identify factors related to repeatability.
Thirty eyes with high myopia and 34 eyes of healthy subjects were included in the study. The mean age in high myopia and control subjects was 55.5 and 60.8 years, respectively, the mean spherical equivalent was -9.98 and -0.55 diopters, and the mean axial length was 28.0 and 23.9 mm. The ICCs of FAZ area of the superficial capillary plexus (SCP) were 0.891 and 0.919, while the CVs were 8.8% and 8.5%. In measurement of the deep capillary plexus, the ICCs were 0.788 and 0.907, while the CVs were 11.2% and 11.0%, which were acceptable but exhibited lower repeatability than those of SCP. Multivariate analyses showed that older age ( = 0.030) and greater axial length ( = 0.005) were significantly associated with lower repeatability of SCP FAZ area measurements. In addition, greater axial length ( = 0.044) was a significant factor for lower repeatability of deep capillary plexus FAZ area measurements.
Manual measurement of FAZ area using OCTA exhibited relatively good repeatability for high myopia. Age and axial length affected repeatability and should be considered when analyzing FAZ areas in high myopia patients.
分析高度近视患者光学相干断层扫描血管造影（OCTA）图像中黄斑无血管区（FAZ）面积手动测量的重复性。
本研究纳入了高度近视患者和对照组。使用OCTA获取浅层和深层毛细血管丛连续两个FAZ面积。评估组内相关系数（ICC）和变异系数（CV），并进行单变量和多变量广义线性混合模型以确定与重复性相关的因素。
本研究纳入了30只高度近视眼睛和34只健康受试者眼睛。高度近视组和对照组的平均年龄分别为55.5岁和60.8岁，平均等效球镜分别为-9.98和-0.55屈光度，平均眼轴长度分别为28.0和23.9毫米。浅层毛细血管丛（SCP）FAZ面积的ICC分别为0.891和0.919，而CV分别为8.8%和8.5%。在深层毛细血管丛测量中，ICC分别为0.788和0.907，而CV分别为11.2%和11.0%，虽可接受但重复性低于SCP。多变量分析显示，年龄较大（P = 0.030）和眼轴长度较长（P = 0.005）与SCP FAZ面积测量重复性较低显著相关。此外，眼轴长度较长（P = 0.044）是深层毛细血管丛FAZ面积测量重复性较低的一个显著因素。
使用OCTA手动测量高度近视患者的FAZ面积具有相对较好的重复性。年龄和眼轴长度会影响重复性，在分析高度近视患者的FAZ面积时应予以考虑。
