School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK.
Vision and Hearing Sciences Research Centre, Anglia Ruskin University, East Road, Cambridge, UK.
Behav Res Methods. 2024 Aug;56(5):4883-4892. doi: 10.3758/s13428-023-02225-y. Epub 2023 Sep 11.
Standard automated perimetry, a psychophysical task performed routinely in eyecare clinics, requires observers to maintain fixation for several minutes at a time in order to measure visual field sensitivity. Detection of visual field damage is confounded by eye movements, making the technique unreliable in poorly attentive individuals and those with pathologically unstable fixation, such as nystagmus. Microperimetry, which utilizes 'partial gaze-contingency' (PGC), aims to counteract eye movements but only corrects for gaze position errors prior to each stimulus onset. Here, we present a novel method of visual field examination in which stimulus position is updated during presentation, which we refer to as 'continuous gaze-contingency' (CGC). In the first part of this study, we present three case examples that demonstrate the ability of CGC to measure the edges of the physiological blind spot in infantile nystagmus with greater accuracy than PGC and standard 'no gaze-contingency' (NoGC), as initial proof-of-concept for the utility of the paradigm in measurements of absolute scotomas in these individuals. The second part of this study focused on healthy observers, in which we demonstrate that CGC has the lowest stimulus positional error (gaze-contingent precision: CGC = ± 0.29°, PGC = ± 0.54°, NoGC = ± 0.81°). CGC test-retest variability was shown to be at least as good as both PGC and NoGC. Overall, CGC is supported as a reliable method of visual field examination in healthy observers. Preliminary findings demonstrate the spatially accurate estimation of visual field thresholds related to retinal structure using CGC in individuals with infantile nystagmus.
标准自动视野检查是眼科诊所常规进行的一种心理物理学任务，要求观察者在每次测量视野敏感度时保持固定注视几分钟。由于眼球运动的干扰，视野损伤的检测结果会产生偏差，使得该技术在注意力不集中或固视不稳定（如眼球震颤）的个体中不可靠。微视野计利用“部分固视偶然性”（PGC）来对抗眼球运动，但仅在每个刺激开始前校正注视位置误差。在这里，我们提出了一种新的视野检查方法，其中在呈现过程中更新刺激位置，我们称之为“连续固视偶然性”（CGC）。在本研究的第一部分，我们展示了三个案例示例，证明了 CGC 能够比 PGC 和标准的“无固视偶然性”（NoGC）更准确地测量婴儿眼球震颤的生理盲点边缘，初步证明了该范式在这些个体的绝对暗点测量中的实用性。本研究的第二部分侧重于健康观察者，我们证明 CGC 具有最低的刺激位置误差（固视偶然性精度：CGC = ±0.29°，PGC = ±0.54°，NoGC = ±0.81°）。CGC 的测试-重测可变性至少与 PGC 和 NoGC 一样好。总之，CGC 支持作为一种在健康观察者中进行视野检查的可靠方法。初步研究结果表明，CGC 可在婴儿眼球震颤患者中精确地估计与视网膜结构相关的视野阈值。
