Kang Sarah L, Beylergil Sinem B, Otero-Millan Jorge, Shaikh Aasef G, Ghasia Fatema F
Case Western Reserve University School of Medicine, Cleveland, USA.
Johns Hopkins University, Baltimore, USA.
J Eye Mov Res. 2019 Jul 5;12(6). doi: 10.16910/jemr.12.6.9.
Fixational eye movements comprise of fast microsaccades alternating with slow intersaccadic drifts. These physiologic eye movements play an important role in visual perception. Amblyopic patients are known to have fixation instability, particularly of the amblyopic eye. We examined eye movement abnormalities that contribute to this instability. We found that fixation stability is affected by the presence of fusion maldevelopment nystagmus (FMN). However, some amblyopes can have nystagmus without nasally directed slow phases and reversal in direction of the quick phase on ocular occlusion, features seen in FMN. In patients without nystagmus, we found increased amplitude of fixational saccades and inter-saccadic drifts. We categorized amblyopia patients by type (anisometropic, strabismic, or mixed) and eye movement waveform (no nystagmus, nystagmus without FMN, and FMN). We found specific fast and slow eye movement abnormalities of the fellow and amblyopic eye during fellow, amblyopic and both eyes viewing conditions across eye movement waveforms and types of amblyopia. These eye movement abnormalities can serve as biomarkers that can predict the impact of amblyopia as measured by visual acuity and stereopsis. Evaluation of fixational eye movements in amblyopia could be important to diagnose these common eye diseases and predict treatment effectiveness.
注视性眼动由快速微扫视和缓慢的扫视间漂移交替组成。这些生理性眼动在视觉感知中起重要作用。已知弱视患者存在注视不稳定，尤其是弱视眼。我们研究了导致这种不稳定的眼动异常。我们发现注视稳定性受融合发育不良性眼球震颤（FMN）的影响。然而，一些弱视患者可出现无向鼻侧慢相的眼球震颤，且在单眼遮盖时快相方向反转，这些是FMN的特征表现。在无眼球震颤的患者中，我们发现注视性扫视和扫视间漂移的幅度增加。我们根据弱视类型（屈光参差性、斜视性或混合型）和眼动波形（无眼球震颤、无FMN的眼球震颤和FMN）对弱视患者进行分类。我们发现在不同的眼动波形和弱视类型中，在注视眼、弱视眼和双眼注视条件下，健眼和弱视眼存在特定的快速和慢速眼动异常。这些眼动异常可作为生物标志物，用于预测弱视对视敏度和立体视测量的影响。评估弱视患者的注视性眼动对于诊断这些常见眼病和预测治疗效果可能很重要。
