School of Optometry & Vision Science, Faculty of Medicine and Health Sciences, The University of Auckland, Auckland, New Zealand.
Department of Psychology, Northeastern University, Boston, MA, USA.
Clin Exp Optom. 2023 Sep;106(7):769-776. doi: 10.1080/08164622.2022.2134763. Epub 2022 Nov 14.
Horizontal fusional reserves are used in the diagnosis and monitoring of common vergence disorders, such as convergence insufficiency, which can cause asthenopia and impact near work. Infrared eyetracking technology shows promise for obtaining automated and objective measurements of fusional reserves, expanding options for screening, clinical testing, and at-home monitoring/vision training.
Current clinical tests for fusional reserves rely on subjective judgements made by patients (for diplopia) and clinicians (for eye movements). This paper describes an objective and automated "digital fusion-range test" pilot-tested in adults without current eye disease or binocular vision anomalies. This test combines a consumer-grade infrared eyetracker, a dichoptic display, and custom analyses programs to measure convergence and divergence reserves.
Twenty-nine adult participants completed the study. Horizontal fusional reserves at 55 cm were measured using prism bars and with our computer-based digital fusion-range test. For the digital test, observers viewed dichoptic targets whose binocular disparity modulated over time (at speeds of 0.5, 1.0, or 2.0 Δ/s) while their eye movements were continuously recorded. Subjective reports of break and recovery (by keyboard button press) were compared to objective estimates extracted from eyetracking recordings (via automated analyses).
Objective and subjective measures of break and recovery agreed closely. Clinically small (0.3-2Δ) but statistically significant (p < 0.012) differences were found between measurement types for divergence breaks/recoveries and convergence recoveries. No significant differences were found for convergence breaks (p = 0.11). Such differences are consistent with an average 0.91 (SD 1.66) seconds delay between objective break/recovery and subjective responses. The digital test produced comparable results to the standard clinical prism bar method.
The digital fusion-range test supports an automated, reliable assessment of horizontal fusional reserves, which do not depend on subjective responses. This technology may prove useful in a variety of clinical and community-based settings.
水平融合储备用于诊断和监测常见聚散障碍，例如集合不足，这可能导致视疲劳并影响近距工作。红外眼动追踪技术有望获得融合储备的自动和客观测量，从而扩大筛选、临床测试和家庭监测/视力训练的选择。
目前用于融合储备的临床测试依赖于患者（用于复视）和临床医生（用于眼球运动）的主观判断。本文描述了一种针对无当前眼部疾病或双眼视觉异常的成年人进行的客观、自动的“数字融合范围测试”的试点研究。该测试结合了消费级红外眼动追踪器、双眼显示和定制分析程序，以测量集合和散开储备。
29 名成年参与者完成了这项研究。使用棱镜棒和我们基于计算机的数字融合范围测试测量 55cm 处的水平融合储备。对于数字测试，观察者观察双眼视差随时间调制的双眼目标（速度为 0.5、1.0 或 2.0Δ/s），同时连续记录他们的眼球运动。通过键盘按钮按下进行的主观报告的突破和恢复与从眼动记录中提取的客观估计（通过自动分析）进行比较。
客观和主观的突破和恢复测量值非常接近。在发散突破/恢复和集合恢复方面，测量类型之间存在临床小（0.3-2Δ）但统计学显著（p<0.012）的差异。在集合突破方面没有发现显著差异（p=0.11）。这些差异与客观突破/恢复和主观反应之间平均 0.91（SD 1.66）秒的延迟一致。数字测试产生的结果与标准临床棱镜棒方法相当。
数字融合范围测试支持水平融合储备的自动、可靠评估，该评估不依赖于主观反应。这项技术在各种临床和社区环境中可能很有用。
