Snapshot Retinal Imaging Mueller Matrix Polarimeter

快照视网膜成像 Mueller 矩阵旋光计

• 批准号: 8772768
• 负责人: Michael Kudenov
• 金额: $ 19.84万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8772768
• 关键词: Algorithms; Animal Model; Area; Arizona; Atrophic; Biological Preservation; Birefringence; California; Clinic; Clinical Sensitivity; Clinical Trials; Complex; Data Set; Defect; Detection; Devices; Diagnosis; Disease; Early Diagnosis; Early Intervention; Early treatment; Eye; Fiber; Fundus; Glaucoma; Health; Human; Image; Imagery; Imaging technology; Institutes; Lasers; Light; Measurement; Measures; Mechanics; Modality; Modeling; Morphologic artifacts; Motion; Neighborhoods; North Carolina; Ophthalmoscopy; Optic Disk; Optical Coherence Tomography; Optics; Oryctolagus cuniculus; Pathologic; Patients; Performance; Property; Public Health; Research; Research Project Grants; Resolution; Retina; Retinal; Scanning; Science; Sensitivity and Specificity; Software Engineering; Structure; Surgeon; Symptoms; System; Technology; Testing; Thick; Time; Universities; Vision; Visual Fields; Visual impairment; base; college; comparative; cost; cost effective; design; experience; image registration; imaging modality; improved; instrument; novel; polarimetry; prototype; retinal nerve fiber layer; screening; two-dimensional

DESCRIPTION (provided by applicant): Worldwide, over 65 million people suffer visual impairment from glaucoma. Because the vast majority of patients rarely experience symptoms of glaucoma until relatively late in the disease, early diagnosis and treatment is essential in preserving vision. Currently, the diagnosis of glaucoma is based on a combination of structural optic disc changes and functional visual field changes. Unfortunately, both of these tests are relatively subjective and definitive diagnosis of glaucoma can be delayed or missed as a result. However, it is well accepted that defects in the retinal nerve fiber layer (RNFL; i.e. structural changes) precede the onset of visual field loss by as much as six years. A number of imaging methods including confocal scanning laser ophthalmoscopy (cSLO), optical coherence tomography (OCT) and scanning laser polarimetry (SLP) have been developed to allow early detection of these subtle structural defects. Of these, SLP provides promise in achieving the earliest detection of glaucoma-induced retinal changes. However, since SLP is not a complete polarimeter, its measurements are prone to error due to the RNFL's diattenuation and depolarization. Thus, accuracy of the SLP's retardance distribution is influenced by the unknown retinal diattenuation and depolarization, decreasing the device's sensitivity and specificity. Furthermore, commercial SLPs only image small sections of the retina in the neighborhood of the optic nerve head, suffer from motion artifacts, and are expensive (estimated cost of $17k using commercial off-the-shelf (COTS) parts and mechanical scanners). We have overcome these limitations with a less expensive (estimated $10k using COTS parts), complete Mueller matrix (MM) polarimeter with no moving parts: the Snapshot Retinal Imaging Mueller Matrix (SRIMM) polarimeter. This device avoids temporal scanning and allows a real-time measurement of the retina's complete polarization state over a large field of view. This device has several advantages. First, the device's cost reduction may make it a more practical and cost-effective instrument for screening patients. Second, since the design has no temporal scanning, large retinal areas can be observed, in a single fundus snapshot, without the need for complex image registration algorithms. Third, the ability to acquire a complete MM data set with high temporal resolution will improve the clinical sensitivity and specificity of this device by removing measurement errors related to depolarization and diattenuation. This is a collaborative effort between North Carolina State University, USC Eye Institute, and the University of Arizona. The specific aims are 1. Design, calibrate, validate and test a fundus camera prototype of a Snapshot Retinal Imaging Mueller Matrix (SRIMM) polarimeter. 2. Design and build a model eye to characterize and validate the performance of the polarimeter. 3. Validate the SRIMM polarimeter's performance in a rabbit model and in a limited number of human patients via comparative measurements taken with a high-resolution SD-OCT and a Zeiss GDx.

描述(申请人提供)：全球有超过6500万人因青光眼而视力受损。由于绝大多数患者很少出现青光眼症状，直到疾病相对较晚的时候，早期诊断和治疗对于保护视力至关重要。目前，青光眼的诊断是基于结构视盘改变和功能视野改变的组合。不幸的是，这两种测试都是相对主观的，因此青光眼的明确诊断可能会被推迟或错过。然而，众所周知，视网膜神经纤维层的缺陷(RNFL；即结构变化)早于视野丧失的开始，长达六年之久。许多成像方法，包括共焦激光眼底扫描(CSLO)、光学相干断层扫描(OCT)和扫描激光偏振(SLP)已经被开发出来，以便能够及早发现这些细微的结构缺陷。其中，SLP在最早发现青光眼引起的视网膜变化方面提供了希望。然而，由于SLP不是一个完整的偏振仪，由于RNFL的去衰减和去偏振，它的测量容易产生误差。因此，SLP延迟分布的准确性受到未知视网膜衰减和去极化的影响，从而降低了设备的灵敏度和特异度。此外，商用SLP只对视神经头附近的小段视网膜进行成像，存在运动伪影，而且价格昂贵(使用商用现成(COTS)部件和机械扫描仪估计成本为1.7万美元)。我们已经克服了这些限制，推出了一种价格更低(使用COTS部件估计为10,000美元)、没有移动部件的完整Mueller矩阵(MM)偏振仪：Snapshot视网膜成像Mueller矩阵(SRIMM)偏振仪。该设备避免了时间扫描，并允许在大视野内实时测量视网膜的完整偏振状态。这种设备有几个优点。首先，该设备的成本降低可能使其成为一种更实用、更具成本效益的筛查患者的工具。其次，由于该设计没有时间扫描，因此可以在一次眼底快照中观察到大片视网膜区域，而不需要复杂的图像配准算法。第三，获得高时间分辨率的完整MM数据集的能力将通过消除与去极化和去衰减相关的测量误差来提高该设备的临床敏感性和特异性。这是北卡罗来纳州立大学、南加州大学眼科研究所和亚利桑那大学的合作成果。具体目标是：1.设计、标定、验证和测试Snapshot视网膜成像Mueller矩阵(SRIMM)偏振仪的眼底相机样机。2.设计并制作了模型眼，对旋光仪的性能进行了表征和验证。3.通过高分辨率SD-OCT和蔡司GDX的对比测量，验证SRIMM旋光仪在兔模型和有限数量的人类患者中的性能。