Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin.
School of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin.
Optom Vis Sci. 2022 Feb 1;99(2):127-136. doi: 10.1097/OPX.0000000000001854.
Foveal avascular zone (FAZ) area is a frequently used biomarker in diseases impacting the retinal vasculature in pediatric populations. Variation in axial length between individuals results in differences in lateral image scale, which affect the accuracy of FAZ area measurements. Accordingly, changes in axial length over time within individual children would affect estimates of FAZ area change.
This study aimed to quantify how changes in axial length over time affect estimates of FAZ area change using optical coherence tomography angiography (OCT-A) images.
Twenty pediatric participants (<18 years old) and 40 adult participants were imaged on Optovue's Avanti system (Fremont, CA) and had axial length measurements acquired at two time points. The FAZ was segmented twice using the OCT-A image at each time point. Foveal avascular zone area was estimated at both time points using the assumed/fixed axial length of the OCT-A device (unscaled) and using the participant's axial length (scaled). Changes in FAZ area over time were compared between the pediatric and adult groups using both unscaled and scaled data.
The average ± standard deviation follow-up time was 3.35 ± 1.66 years for the pediatric group and 2.90 ± 1.65 years for the adult group. Using unscaled data, FAZ area seemed to decrease between visits in the pediatric group (P = .004), whereas the FAZ area increased between visits in the adult group (P = .003). When correctly scaled data were used, the FAZ area still increased between visits for the adult group (P < .001), although the FAZ area no longer showed a significant change between visits for the pediatric group (P = .37). When comparing the normalized FAZ area change across visits between unscaled and scaled data, a significant difference was found between the adult and pediatric groups (P < .001).
Scaled data should be used when measuring FAZ area in pediatric populations, especially in longitudinal studies.
黄斑中心凹无血管区（FAZ）面积是一种常用于儿科人群中影响视网膜血管疾病的生物标志物。个体之间眼轴长度的差异会导致横向图像比例的差异，从而影响 FAZ 面积测量的准确性。因此，个体儿童内眼轴长度随时间的变化会影响 FAZ 面积变化的估计。
本研究旨在通过光学相干断层扫描血管造影（OCT-A）图像量化眼轴长度随时间的变化如何影响 FAZ 面积变化的估计。
20 名儿科参与者（<18 岁）和 40 名成年参与者在 Optovue 的 Avanti 系统（加利福尼亚州弗里蒙特）上进行成像，并在两个时间点获得眼轴长度测量值。在每个时间点，使用 OCT-A 图像两次对 FAZ 进行分割。使用 OCT-A 设备的假定/固定眼轴长度（未缩放）和参与者的眼轴长度（缩放）两次估算 FAZ 面积。使用未缩放和缩放数据比较儿童和成年组之间随时间的 FAZ 面积变化。
儿科组的平均随访时间±标准偏差为 3.35±1.66 年，成年组为 2.90±1.65 年。使用未缩放数据，FAZ 面积似乎在儿科组随访期间减少（P=0.004），而 FAZ 面积在成年组随访期间增加（P=0.003）。当使用正确缩放的数据时，FAZ 面积在成年组随访期间仍增加（P<0.001），尽管 FAZ 面积在儿科组随访期间不再显示显著变化（P=0.37）。当比较未缩放和缩放数据在访问之间的归一化 FAZ 面积变化时，在成年和儿科组之间发现了显著差异（P<0.001）。
在儿科人群中测量 FAZ 面积时，应使用缩放数据，尤其是在纵向研究中。
