Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States; San Giuseppe Eye Clinic, Milan, Italy; University of Milan, Milan, Italy.
Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States.
Prog Brain Res. 2019;249:235-248. doi: 10.1016/bs.pbr.2019.04.024. Epub 2019 Jun 20.
Amblyopic patients are known to have fixation instability, particularly of the amblyopic eye. The stability of the fixation is affected by the presence of nystagmus, the frequency and amplitude of fixational saccades and inter-saccadic drifts. Amblyopic patients without nystagmus have increased amplitude of the fixational saccades with reduced frequency of the physiologic microsaccades and have increased inter-saccadic drifts. Amblyopia patients who have experienced a disruption in binocularity in early infancy develop fusion maldevelopment nystagmus (FMN) previously called latent nystagmus as it is more evident during monocular viewing conditions. We have found that some amblyopic patients can have nystagmus with slow phases that are not directed nasally and without the reversal in direction on ocular occlusion, features seen in patients with FMN. The current mainstay of amblyopia treatment comprises of part-time occlusion therapy of the non-amblyopic eye. The amount of patching treatment is in the range of 2-6h/day as determined by the severity of amblyopia. Despite treatment, up to 40% of patients have residual amblyopia. We analyzed the effectiveness of part-time occlusion therapy in amblyopic patients as a function of fixation instability. We categorized amblyopic patients based on their eye movement waveforms obtained during a visual fixation task into those lacking nystagmus, those with FMN and those with nystagmus but no FMN. We did a retrospective chart review to gather information about their clinical characteristics and treatment response. We found that patients with FMN require a more prolonged duration of treatment and have a poorer recovery of stereopsis compared to patients with nystagmus but no FMN and patients lacking nystagmus. This study suggests that eye movement assessment provides valuable information in the management of amblyopia.
弱视患者的固视不稳定是众所周知的，尤其是弱视眼。固视的稳定性受到眼球震颤、固视性眼跳的频率和幅度以及眼跳间漂移的影响。没有眼球震颤的弱视患者，固视性眼跳的幅度增加，生理性微扫视的频率降低，眼跳间漂移增加。在婴儿早期经历双眼视功能破坏的弱视患者会发展出融合发育性眼球震颤（FMN），以前称为潜伏性眼球震颤，因为在单眼观察条件下更为明显。我们发现，一些弱视患者可能会出现慢相不是向鼻侧的眼球震颤，并且在眼球遮盖时方向不反转，这些特征见于 FMN 患者。目前弱视治疗的主要方法包括非弱视眼的部分时间遮盖治疗。遮盖治疗的时间量在 2-6 小时/天之间，具体取决于弱视的严重程度。尽管进行了治疗，但仍有高达 40%的患者存在残余弱视。我们分析了部分时间遮盖治疗在弱视患者中的效果，作为固视不稳定的一个功能。我们根据患者在视觉固视任务中获得的眼动波型，将弱视患者分为无眼球震颤、FMN 和无 FMN 但有眼球震颤的患者。我们进行了回顾性图表审查，以收集有关他们的临床特征和治疗反应的信息。我们发现，与无 FMN 但有眼球震颤的患者和无眼球震颤的患者相比，FMN 患者需要更长时间的治疗，并且立体视的恢复更差。这项研究表明，眼球运动评估为弱视的治疗提供了有价值的信息。
