Mechanisms and plasticity of long term visual adaptation to ocular optics

长期视觉适应眼光学的机制和可塑性

• 批准号: 8504254
• 负责人: GEUNYOUNG YOON
• 金额: $ 35.7万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-02 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8504254
• 关键词: Address; Adult; Adverse effects; Affect; Blindness; Classification; Complement; Complex; Contrast Sensitivity; Cornea; Corneal Diseases; Data; Defect; Discrimination; Eye; Frequencies; Gases; Goals; Human; Image; Judgment; Keratoconus; Letters; Long-Term Effects; Measurement; Measures; Methodology; Methods; Modeling; Neuronal Plasticity; Noise; Optics; Patients; Pattern; Perception; Perceptual Masking; Performance; Phase; Play; Population; Process; Property; Psychophysics; Regimen; Research; Retina; Retinal; Role; Stimulus; System; Testing; Time; Training; Vision; Visual; Visual Acuity; Visual system structure; Work; adaptive optics; base; design; experience; image processing; improved; innovation; insight; lens; luminance; monocular; neuroadaptation; novel; public health relevance; relating to nervous system; research study; response; spatial vision; theories; tool; visual adaptation; visual deprivation; visual optics; visual performance; visual process; visual processing; visual stimulus

DESCRIPTION (provided by applicant): In eyes with prolonged visual deprivation induced by the abnormally large optical defects such as aberrations, the actual visual performance after precise correction of remaining aberrations is significantly poorer than that predicted from optical theory and that measured in normal eyes. This unexplained vision loss suggests that the degraded image quality received by the eyes alters neural processing of images formed on the retina, which plays an important role in determining perceived visual quality. We hypothesize that the post-correction functional measurements on a given patient are biased by long-term neural adaptation to the poor retinal image quality that the patient may have progressively experienced before correction. We will test this hypothesis using a corneal disease, keratoconus as a model of long-term visual adaptation. The visual system of this unique patient group developed normally but, during adulthood, has gradually experienced severely degraded image quality by the large magnitude of aberrations for a prolonged period of time. The proposed project implements the latest tools and advances in human optics research to investigate (1) the mechanisms underlying long-term neural adaptation to degraded optical quality of the eye and (2) neural plasticity resulting from improved optics and/or visual training paradigms. We will use two innovative advanced correction tools: an adaptive optics vision simulator and a customized scleral lens for short-term and long-term precise aberration correction, respectively. Aim 1 is designed to investigate the mechanisms that underlie long-term neural adaptation to the optically degraded retinal image quality and their impact on neural processing of image quality by (1.1) testing the hypothesis that the neural system is capable to compensate for losses in image quality due to the ocular aberration through long-term adaptation to phase spectra using broadband stimuli, acuity letters and natural images (1.2) characterizing long-term adaptation induced-changes in the key properties of basic spatial vision mechanisms using narrow band visual stimuli i.e. gratings and (1.3) examining the effects of long-term neural adaptation on the two eyes being integrated with regard to the monocular functions including visual acuity, contrast perception at and above threshold before and after aberration correction. Aim 2 will assess the extent to which plasticity that occurs during long-term adaptation is reversible and what mechanistic changes underlie this reversal once aberration-free image quality is achieved in KC eyes. (2.1) We will first quantify the time course of "passive" neural re-adaptation to improved ocular optics achieved by wearing customized aberration correcting scleral lens daily. We will also apply different visual training paradigms based on (2.2) narrow (single spatial frequency gratings) and (2.3) broad (natural images) band visual stimuli to differentiate different mechanisms of neural plasticity and to test the hypothesis that visual performance can further be improved by the visual training. Binocular transfer of the monocular neural manipulation through visual training effects will also be examined.

描述（由申请人提供）：在由异常大的光学缺陷（如像差）引起的长期视觉剥夺的眼睛中，精确矫正剩余像差后的实际视觉性能明显低于光学理论预测的和正常眼睛中测量的视觉性能。这种无法解释的视力丧失表明，眼睛接收到的图像质量下降改变了视网膜上形成的图像的神经处理，这在确定感知的视觉质量方面起着重要作用。我们假设，对一个给定的患者的矫正后的功能测量是有偏见的长期神经适应不良的视网膜图像质量，患者可能已经逐步经历矫正前。我们将使用角膜疾病圆锥角膜作为长期视觉适应的模型来检验这一假设。这个独特的患者群体的视觉系统发育正常，但在成年期，由于长时间的大幅度像差，逐渐经历了严重的图像质量下降。拟议的项目实施了人类光学研究的最新工具和进展，以研究（1）长期神经适应眼睛光学质量下降的机制和（2）改善光学和/或视觉训练范式导致的神经可塑性。我们将使用两种创新的先进矫正工具：自适应光学视觉模拟器和定制的巩膜透镜，分别用于短期和长期的精确像差矫正。目的1旨在通过以下方法研究视网膜图像质量光学退化的长期神经适应机制及其对图像质量神经处理的影响：（1.1）测试神经系统能够通过使用宽带刺激对相位谱的长期适应来补偿由于眼像差引起的图像质量损失的假设，视力字母和自然图像（1.2）使用窄带视觉刺激（即光栅）表征基本空间视觉机制的关键特性的长期适应诱导的变化，以及（1.3）检查长期神经适应对正被整合的双眼的单眼功能（包括视敏度）的影响，在像差校正之前和之后的阈值处和阈值以上的对比度感知。目标2将评估在长期适应过程中发生的可塑性是可逆的程度，以及一旦在KC眼中实现无像差图像质量，这种逆转的机制变化。(2.1)我们将首先量化“被动”神经再适应的时间进程，以改善通过每天佩戴定制的像差矫正巩膜透镜实现的眼睛光学。我们还将应用基于（2.2）窄（单空间频率光栅）和（2.3）宽（自然图像）带视觉刺激的不同视觉训练范例，以区分不同的 神经可塑性的机制，并验证视觉操作可以通过视觉训练进一步改善的假设。通过视觉训练效果的单眼神经操作的双眼转移也将被检查。