Improved Assessment of Visual Field Change

描述(由申请人提供)： 项目概述：问题：在美国，青光眼是导致失明的主要原因。青光眼和其他视神经疾病的治疗决定在很大程度上是基于视野的量化对视觉功能的改变。视野变化的可靠识别是视力检测中最难解决的一个问题。使用标准视野计，在中度视野损害的区域，重新测试的变异性大于仪器的物理动态范围，视网膜神经纤维层变得如此薄，以至于无法用当前的OCT成像技术进行测量。然而，视觉功能往往保留在这些受损的区域。我们已经证明，增加刺激大小可以降低重测变异性，同时保持相同的灵敏度来检测新的缺陷，并将测试的有用动态范围扩展约50%。假设：使用不同大小的刺激激活视觉感受野的模型，可以预测使用更大的周边刺激可以改善信噪比。我们认为，很大一部分周界可变性和狭窄的有效动态范围是由于使用小刺激导致的信噪比较低。使用更大的视野刺激将增强视野检查的动态范围，同时降低重新测试的可变性，从而更好地和更早地检测视野变化。我们将使用刺激大小III、V、VI和亮度大小阈值视野检查对120名青光眼患者和60名正常人进行自动视野检查，这是一种通过改变刺激大小而不是亮度来确定视觉阈值的测试。方法：具体目标1：确定变异性最小、有效动态范围最大的刺激大小。我们将定义、测量和比较视野检查与刺激大小III、V、VI和亮度大小阈值视野检查的有效动态范围和重测变量；50名受试者(40名青光眼患者和10名健康受试者)将每周接受一次为期五周的测试。具体目标2：通过对患者进行纵向测试，确定在患者病程中最早显示视野变化的刺激大小。我们将使用线性回归和可信区间以及我们的统计模型(特定目标3)来确定在我们最近的优点回顾的180名受试者队列中，哪种刺激大小最早检测到视野变化。具体目标3：建立视野变化的统计模型。当前技术错误地假设视野测试位置是独立的。使用贝叶斯和频率分析工具，我们将建立一个指数空间相关性结构来模拟随时间推移的视野数据。摘要：我们预计将显著增加视野检查的有效动态范围和检测视野变化的能力。对退伍军人医疗保健的潜在影响：这些方法将通过以下方式影响退伍军人医疗保健：(1)允许更早地发现视野变化；(2)最大限度地减少误诊、不必要的检查，甚至因错误地将视野波动解释为变化而导致的不必要的手术；(3)使临床试验和退伍军人视力康复计划能够更好地评估视觉功能。

DESCRIPTION (provided by applicant): Project Summary: Problem: Glaucoma is a leading cause of blindness in the United States. Treatment decisions for glaucoma and other optic nerve diseases are based largely on changes in visual function made by quantification of the visual field. The reliable identification of visual field change is the single most difficult problem in vision testing. With standard perimetry, in areas of moderate visual field damage, retest variability is greater than the physical dynamic range of the instrument and the retinal nerve fiber layer becomes so thin that it is not measurable by current OCT imaging techniques. However, visual function often remains in these damaged areas. We have shown that increasing the stimulus size can lower retest variability while maintaining the same sensitivity to detect new deficits, and extend the useful dynamic range of testing by about 50%. Hypothesis: Using a model of visual receptive field activation by different sized stimuli predicts an improved signal-to-noise ratio using larger perimetric stimuli. We propose that a large portion of perimetric variability and narrow effective dynamic range is due to a poor signal-to-noise ratio associated with using a small stimulus. Using larger perimetric stimuli will enhance the dynamic range of perimetry while lowering retest variability allowing for improved and earlier detection of visual field change. We will test a cohort of 120 glaucoma patients and 60 normals with automated perimetry using stimulus sizes III, V, VI and luminance size threshold perimetry a test that finds a visual threshold by changing stimulus size rather than luminance. Methods: Specific Aim 1: Identify the stimulus size with the lowest variability and broadest effective dynamic range. We will define, measure and compare the effective dynamic ranges and retest variabilities of perimetry with stimulus sizes III, V, VI and luminance size threshold perimetry; 50 subjects (40 glaucoma patients and 10 healthy participants) will be tested once a week for five weeks. Specific Aim 2: Identify the stimulus size that shows visual field change earliest in a patients' course by testing patients longitudinally. We will use linear regression and confidence intervals along with our statistical model (Specific Aim 3) to determine which stimulus size detects visual field change at the earliest time in our 180 subject cohort from our recent Merit Review. Specific Aim 3: Develop a statistical model of visual field change. Current techniques incorrectly assume visual field test locations are independent. Using Bayesian and Frequentist analytical tools we will build an exponential spatial correlation structure to model visual field data over time. Summary: We anticipate substantially increasing both the useful dynamic range of perimetry and our ability to detect visual field change. Potential Impact on Veterans Health Care: These methods would impact VA health care by (1) allowing earlier detection of visual field change; (2) minimize misdiagnosis, unnecessary testing and even unnecessary surgery that results from mistakenly interpreting fluctuation of the visual field as change; (3) allow better evaluation of visual function for clinical trials and VA vision rehabilitation programs.