Blekher Tanya, Weaver Marjorie R, Cai Xueya, Hui Siu, Marshall Jeanine, Jackson Jacqueline Gray, Wojcieszek Joanne, Yee Robert D, Foroud Tatiana M
Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Invest Ophthalmol Vis Sci. 2009 Dec;50(12):5707-11. doi: 10.1167/iovs.09-3538. Epub 2009 Jun 24.
Abnormalities in saccades appear to be sensitive and specific biomarkers in the prediagnostic stages of Huntington disease (HD). The goal of this study was to evaluate test-retest reliability of saccadic measures in prediagnostic carriers of the HD gene expansion (PDHD) and normal controls (NC).
The study sample included 9 PDHD and 12 NC who completed two study visits within an approximate 1-month interval. At the first visit, all participants completed a uniform clinical evaluation. A high-resolution, video-based system was used to record eye movements during completion of a battery of visually guided, antisaccade, and memory-guided tasks. Latency, velocity, gain, and percentage of errors were quantified. Test-retest reliability was estimated by calculating the intraclass correlation (ICC) of the saccade measures collected at the first and second visits. In addition, an equality test based on Fisher's z-transformation was used to evaluate the effects of group (PDHD and NC) and the subject's sex on ICC.
The percentage of errors showed moderate to high reliability in the antisaccade and memory-guided tasks (ICC = 0.64-0.93). The latency of the saccades also demonstrated moderate to high reliability (ICC = 0.55-0.87) across all tasks. The velocity and gain of the saccades showed moderate reliability. The ICC was similar in the PDHD and NC groups. There was no significant effect of sex on the ICC.
Good reliability of saccadic latency and percentage of errors in both antisaccade and memory-guided tasks suggests that these measures could serve as biomarkers to evaluate progression in HD.
扫视异常似乎是亨廷顿舞蹈症（HD）诊断前阶段敏感且特异的生物标志物。本研究的目的是评估HD基因扩展的诊断前携带者（PDHD）和正常对照（NC）扫视测量的重测信度。
研究样本包括9名PDHD和12名NC，他们在大约1个月的间隔内完成了两次研究访视。在首次访视时，所有参与者都完成了统一的临床评估。使用高分辨率的基于视频的系统在完成一系列视觉引导、反扫视和记忆引导任务期间记录眼动。对潜伏期、速度、增益和错误百分比进行量化。通过计算首次和第二次访视时收集的扫视测量的组内相关系数（ICC）来估计重测信度。此外，使用基于费舍尔z变换的等效性检验来评估组（PDHD和NC）和受试者性别对ICC的影响。
在反扫视和记忆引导任务中，错误百分比显示出中度到高度的信度（ICC = 0.64 - 0.93）。在所有任务中，扫视潜伏期也显示出中度到高度的信度（ICC = 0.55 - 0.87）。扫视速度和增益显示出中度信度。PDHD组和NC组的ICC相似。性别对ICC没有显著影响。
反扫视和记忆引导任务中扫视潜伏期和错误百分比具有良好的信度，表明这些测量可作为评估HD进展的生物标志物。
