Improved Assessment of Visual Field Change

描述（由申请人提供）： 问题：青光眼在美国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策主要基于通过视野的量化而做出的视觉功能的变化。视野变化的可靠识别是视觉测试中最困难的问题。在标准视野检查的情况下，在中度视野损伤的区域中，重新测试的可变性大于仪器的物理动态范围，并且视网膜神经纤维层变得非常薄，以至于无法通过当前的OCT成像技术进行测量。然而，这些受损区域的视觉功能往往仍然存在。我们已经表明，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，以检测新的缺陷，并延长约50%的测试的有用的动态范围。假设：使用不同大小的刺激的视觉感受野激活的模型预测使用较大的周边刺激的改善的信噪比。我们建议，大部分的周长变异性和狭窄的有效动态范围是由于使用一个小的刺激相关联的信号噪声比差。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，从而允许改善和更早地检测视野变化。我们将测试一组120名青光眼患者和60名正常人，使用刺激大小III，V，VI和亮度大小阈值视野检查的自动视野检查，通过改变刺激大小而不是亮度来找到视觉阈值。方法：具体目标1：确定具有最低可变性和最宽有效动态范围的刺激大小。我们将定义，测量和比较有效的动态范围和重新测试的视野变化与刺激大小III，V，VI和亮度大小阈值视野检查; 50名受试者（40名青光眼患者和10名健康参与者）将被测试，每周一次，为期五周。具体目标2：通过纵向测试患者，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置信区间沿着以及我们的统计模型（特定目标3），以确定在我们最近的Merit审查中，哪种刺激大小在我们的180名受试者队列中最早检测到视野变化。具体目标3：开发视野变化的统计模型。目前的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，随着时间的推移模拟视野数据。总结：我们预计将大大增加视野检查的有效动态范围和我们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VA医疗保健：（1）允许更早地检测视野变化;（2）最大限度地减少误诊、不必要的测试甚至不必要的手术，这些手术是由于错误地将视野波动解释为变化而导致的;（3）允许更好地评估临床试验和VA视力康复计划的视功能。

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.