University of California - San Francisco, Department of Neurology, San Francisco, CA, USA.
University of California Berkeley, Vision Science Graduate Group, Berkeley, CA, USA.
Transl Vis Sci Technol. 2022 Feb 1;11(2):35. doi: 10.1167/tvst.11.2.35.
The purpose of this study was to characterize the benign biological variance of fixational microsaccades in a control population using a tracking scanning laser ophthalmoscope (TSLO), accounting for machine accuracy and precision, to determine ideal testing conditions to detect pathologic change in fixational eye motion (FEM).
We quantified the accuracy and precision of the TSLO, analyzing measurements made by three operators on a model eye. Repeated, 10-second retinal motion traces were then recorded in 17 controls, 3 times a day (morning, afternoon, and evening), on 3 separate days. Microsaccade metrics (MMs) of frequency, average amplitude, peak velocity, and peak acceleration were extracted. Trace to trace, interday, and intraday variability were calculated across all subjects.
Intra-operator and machine variation contributed minimally to total variation, with only 0.007% and 0.14% contribution for frequency and amplitude respectively. Bias was detected, with lower accuracy for higher amplitudes. Participants had an average (SD) microsaccade frequency of 0.84 Hz (0.52 Hz), amplitude of 0.32 degrees (0.11 degrees), peak velocity of 43.68 degrees/s (14.02 degrees/s), and peak acceleration of 13,920.04 degrees/s2 (4,186.84 degrees/s2). The first trace recorded within a session significantly differed from the second two in both microsaccade acceleration and velocity (P < 0.05), and frequency was 0.098 Hz higher in the evenings (P < 0.05). There was no MM difference between days and no evidence of a session-level learning effect (P > 0.05).
The TSLO is both accurate and precise. However, biological inter- and intra-individual variance is present. Trace to trace variability and time of day should be accounted for to optimize detection of pathologic change.
本研究旨在使用跟踪扫描激光检眼镜（TSLO）描述对照人群中固视微扫视的良性生物学变异性，考虑到机器精度，以确定检测固视眼动（FEM）病理性变化的理想测试条件。
我们通过三位操作人员对模型眼进行测量，定量评估了 TSLO 的准确性和精密度。然后，在 3 天内每天 3 次（上午、下午和晚上），对 17 名对照者重复记录 10 秒视网膜运动轨迹。提取频率、平均幅度、峰值速度和峰值加速度等微扫视指标（MMs）。计算所有受试者的轨迹间、日间和日内变异性。
操作者内和机器变异对总变异的贡献很小，频率和幅度的变异分别只有 0.007%和 0.14%。检测到偏差，幅度越高，准确性越低。参与者的平均（标准差）微扫视频率为 0.84 Hz（0.52 Hz），幅度为 0.32 度（0.11 度），峰值速度为 43.68 度/s（14.02 度/s），峰值加速度为 13920.04 度/s2（4186.84 度/s2）。在一次试验中，第一个轨迹与后两个轨迹在微扫视加速度和速度上均有显著差异（P < 0.05），并且晚上的频率高出 0.098 Hz（P < 0.05）。日内之间无 MM 差异，也无试验水平学习效应的证据（P > 0.05）。
TSLO 既准确又精确。然而，存在个体间和个体内的生物学变异性。应考虑轨迹间的变异性和时间因素，以优化病理性变化的检测。
