Cleveland Clinic, Cleveland, OH, United States of America.
SUNY College of Optometry, NY, New York, United States of America.
J Neurol Sci. 2022 Oct 15;441:120373. doi: 10.1016/j.jns.2022.120373. Epub 2022 Aug 3.
Amblyopia is a neurodevelopmental disorder caused by abnormal visual experience in early life that affects 3-5% of the population. Amblyopia results in a host of monocular and binocular visual afferent function deficits including reduced visual acuity, contrast sensitivity, depth perception, interocular suppression, and efferent function abnormalities such as unstable and inaccurate fixation. Conventional treatments such as patching therapy and newer dichoptic treatments are not always successful as 30-40% of patients experience recurrence/regression of amblyopia. There are numerous review articles focused on visual afferent function deficits and treatment modalities and outcomes in amblyopia. Recently, the advent of high spatial and temporal resolution eye trackers has spurred studies on fixation eye movements (FEMs) in healthy controls and neurologic and ophthalmic disorders. In this focused review, we will summarize studies evaluating FEM abnormalities in amblyopia. We will first describe the common devices and techniques used to quantify fixation abnormalities, and then highlight the importance of systematically evaluating the eye movements under different viewing conditions and describe the parameters crucial in assessing FEM abnormalities in amblyopia. We will summarize the evidence suggesting that FEM abnormalities are not limited to the amblyopic eye only but also affects the fellow eye and that FEM abnormalities can serve as biomarkers to predict the impact of amblyopia on visual functions. Beyond diagnosis, we will discuss the treatment and prognostic implications of the evaluation of FEM abnormalities in clinical practice.
弱视是一种由早期生活中异常视觉体验引起的神经发育障碍，影响了 3-5%的人群。弱视导致一系列的单眼和双眼视觉传入功能缺陷，包括视力下降、对比敏感度降低、深度知觉、双眼抑制和传出功能异常，如不稳定和不准确的固视。传统的治疗方法，如遮盖疗法和新的双眼治疗方法并不总是成功的，因为 30-40%的患者会出现弱视的复发/回归。有许多综述文章专注于弱视的视觉传入功能缺陷和治疗方法及结果。最近，高空间和时间分辨率眼动追踪器的出现刺激了对健康对照者以及神经和眼科疾病的固视眼动（FEM）的研究。在本次重点综述中，我们将总结评估弱视中 FEM 异常的研究。我们将首先描述用于量化固视异常的常见设备和技术，然后强调在不同观察条件下系统评估眼动的重要性，并描述评估弱视中 FEM 异常的关键参数。我们将总结表明 FEM 异常不仅局限于弱视眼，也影响对侧眼的证据，以及 FEM 异常可作为预测弱视对视觉功能影响的生物标志物。除了诊断之外，我们还将讨论在临床实践中评估 FEM 异常的治疗和预后意义。
