The role of eye-movements in limiting spatial vision in amblyopia

眼球运动在限制弱视空间视力中的作用

• 批准号: 9806821
• 负责人: Dennis Michael Levi
• 金额: $ 22.46万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9806821
• 关键词: Adult; Affect; Amblyopia; Anisometropia; Attention; Blindness; Child; Clinical; Contrast Sensitivity; Crowding; Devices; Eye; Eye Movements; Frequencies; Goals; Human; Impairment; Individual; Infant; Lasers; Letters; Life; Location; Manuals; Measures; Methods; Modeling; Motion; Neurons; Ophthalmoscopes; Performance; Peripheral; Persons; Pilot Projects; Play; Positioning Attribute; Property; Reaction Time; Refractive Errors; Research; Resolution; Retina; Role; Saccades; Scanning; Sensory; Stimulus; Stimulus Deprivation-Induced Amblyopia; Strabismus; Testing; Time; Uncertainty; Vision; Visual; Visual Acuity; Work; area V1; deprivation; developmental disease; effective therapy; experimental study; innovation; interest; novel; novel strategies; relating to nervous system; response; retinal imaging; role model; sample fixation; spatial vision; vision development; visual performance; visual search

Levi, Dennis M. PROJECT SUMMARY/ABSTRACT Amblyopia is a developmental disorder of spatial vision usually associated with the presence of strabismus, anisometropia or form deprivation early in life. It affects visual acuity, contrast sensitivity and position acuity. Amblyopia is clinically important because, aside from refractive error, it is the most frequent cause of vision loss in infants and young children, and amblyopia is of basic interest because it reflects the neural impairment which can occur when normal visual development is disrupted. The long-range objectives of this research are to understand the mechanisms that limit spatial vision in humans with amblyopia, with the ultimate goal of developing new approaches aimed at more effective treatment. While our focus in past studies has been on the sensory losses, here we propose the application of a number of innovative methods that will enable us to test specific hypotheses about the role of eye-movements in limiting spatial vision in amblyopia. Aim 1 tests the hypothesis that abnormal spatial vision is at least in part a consequence of fixational eye movements. Specifically we ask how both the retinal image motion induced by these abnormal fixational eye movements, and the eye movements per se, influence visual resolution, visual acuity, crowding and the precision and accuracy of spatial localization. We will use a high-resolution video eye tracker, the Tracking Scanning Laser Ophthalmoscope (TSLO) which allows stimuli to be delivered to precisely identifiable locations on the retina, to test our hypothesis using three different approaches: i) We will measure, model and characterize fixational eye movements in normal and amblyopic adults while performing visual tasks that are compromised in amblyopia. ii) We will assess the role of retinal image motion by comparing visual performance on these tasks under stabilized, unstabilized and “playback” (i.e., superimposing the amblyopic eye's retinal image motion on the nonamblyopic eye) conditions. iii) We will assess the role of eye movements per se by evaluating visual performance around the time of occurrence of drifts and microsaccades. Compared to normal observers, strabismic amblyopes have significantly longer saccadic and manual latencies to stimuli seen with their amblyopic eyes, compared to their fellow eyes. Aim 2 tests the hypothesis that for strabismic amblyopes, the frequent microsaccades and accompanying saccadic suppression and attentional shifts made while strabismics struggle to maintain fixation with their amblyopic eyes, result in all types of reaction times being irreducibly delayed, commensurate with the degree of unsteadiness. Because the degree of unsteadiness is correlated with LogMAR acuity, it follows that reaction time and saccadic latency are also correlated with LogMAR acuity. Aim 2 tests a number of specific hypotheses regarding the role of microsaccades in reaction time and visual search. 1

作者：Dennis M. 项目总结/摘要 弱视是一种空间视觉发育障碍，通常与斜视有关， 屈光参差或形觉剥夺。它影响视力、对比敏感度和位置敏锐度。 弱视在临床上很重要，因为除了屈光不正，它是视力丧失的最常见原因 在婴幼儿中，弱视是基本感兴趣的，因为它反映了神经损伤， 当正常的视觉发育受到干扰时会发生。这项研究的长期目标是 了解限制弱视人类空间视觉的机制，最终目标是 开发新的治疗方法以获得更有效的治疗效果。 虽然我们在过去的研究中的重点一直是感官的损失，在这里，我们提出了一个应用程序， 一些创新的方法，使我们能够测试有关眼球运动的作用的具体假设 在弱视中限制了空间视觉。 目的1测试的假设，异常的空间视觉至少部分是固视眼的后果 动作具体来说，我们问如何既视网膜图像运动引起的这些异常固视眼 运动和眼球运动本身会影响视觉分辨率、视敏度、拥挤和视力。 空间定位的精度和准确性。我们将使用高分辨率视频眼动仪，跟踪 扫描激光检眼镜（TSLO），可将刺激传递到可精确识别的位置 在视网膜上，使用三种不同的方法来测试我们的假设：i）我们将测量，建模和 表征正常和弱视成人在执行视觉任务时的注视眼球运动， 弱视的危害ii）我们将通过比较视觉表现来评估视网膜图像运动的作用 在稳定、不稳定和“回放”（即，叠加弱视眼视网膜 非弱视眼上的图像运动）条件。iii）我们将通过以下方式评估眼球运动本身的作用： 评估漂移和微扫视发生时的视觉表现。 与正常人相比，斜视性弱视患者的扫视和手动时间明显延长， 与他们的同伴眼睛相比，他们对弱视眼所看到的刺激的宽容度。目标2检验假设 对于斜视性弱视，频繁的微扫视和伴随的扫视抑制， 当斜视患者努力保持与弱视眼的注视时，注意力的转移， 反应时间的类型是不可减少的延迟，与不稳定的程度相称。因为 不稳定的程度与LogMAR敏锐度相关，因此反应时间和扫视潜伏期是 也与LogMAR敏锐度相关。目标2测试了一些关于 反应时间和视觉搜索中的微扫视。 1