Functional and Structural Optical Coherence Tomography for Glaucoma

项目总结 青光眼是导致失明的主要原因。青光眼的早期诊断和密切监测很重要 因为发病是隐蔽的，损害是不可逆转的。先进的成像方式，如光学 相干层析成像(OCT)在过去的二十年中被用来改进客观评价 青光眼。OCT具有比其他后眼成像方式更高的轴向空间分辨率，并且它具有 相对较好的诊断准确性和可重复性测量损伤的神经结构 青光眼。然而，仅用任何成像方式测量结构，对 检测早期青光眼，仅与视野(VF)丧失有中度相关性。使用高速OCT 系统，我们开发了新的方法来成像和测量视神经头(ONH)和视网膜血液 流。初步结果显示室性心动过速损失与测量的视网膜血流量高度相关。 由OCT测量的神经结构比OCT或其他成像方式测量的任何神经结构都要高。因此，世界银行的目标是 建议的项目是通过进一步的开发来提高青光眼的诊断和预后评估 采用超高速(70-100 kHz)OCT技术的新型功能性OCT测量。 具体目标是： 1.改进视网膜血流的多普勒OCT测量方法。乳头周围视网膜的多环状扫描 动脉和静脉在2秒内测量视网膜总血流量。使用更快的OCT系统将允许 自动化测量，提高了重复性。 2.建立ONH的OCT定量血管成像技术。三维(3D)OCT血管成像 通过一种新的分裂谱幅度去相关使之变得实用(在3秒内进行3x3毫米扫描) 算法。初步结果显示，在早期青光眼中，ONH微循环显著丧失。算法 计划改进血管造影术、分割、量化和自动化。 3.测量从ONH到视网膜神经节细胞的神经结构。通过配准多个体积 扫描，我们已经展示了从ONH到ONH的视网膜纤维通路的完整3D特征 黄斑。将开发这些结构的全自动量化。 4.评估先进的OCT技术在临床研究中的应用。功能OCT和结构OCT在我国的应用 青光眼将在150名青光眼和健康受试者的纵向观察研究中进行评估。 将在40名受试者中研究降眼压手术对血流的影响。 视网膜血流量、ONH循环、视盘边缘体积、乳头周围神经纤维层体积以及 黄斑神经节细胞复合体体积均为同一块青光眼拼图。这个项目将会发展 新颖的成像方法，让我们可以使用一种工具-超高速OCT来查看整个图像。

PROJECT SUMMARY Glaucoma is a leading cause of blindness. Early diagnosis and close monitoring of glaucoma are important because the onset is insidious and the damage is irreversible. Advanced imaging modalities such as optical coherence tomography (OCT) have been used in the past 2 decades to improve the objective evaluation of glaucoma. OCT has higher axial spatial resolution than other posterior eye imaging modalities, and it has relatively good diagnostic accuracy and reproducibility in the measurement of neural structures damaged by glaucoma. However, the measurement of structure alone, with any imaging modality, has limited sensitivity for detecting early glaucoma and only moderate correlation with visual field (VF) loss. Using high-speed OCT systems, we have developed new methods to image and measure optic nerve head (ONH) and retinal blood flow. Preliminary results showed that VF loss was more highly correlated with retinal blood flow as measured by OCT than any neural structure measured by OCT or other imaging modality. Accordingly, the goal of the proposed project is to improve the diagnostic and prognostic evaluation of glaucoma by further developing novel functional OCT measurements using ultrahigh-speed (70-100 kHz) OCT technology. The specific aims are: 1. Improve Doppler OCT measurement of retinal blood flow. Multi-circular scans of peripapillary retinal arteries and veins measure total retinal blood flow in 2 seconds. The use of faster OCT systems will allow automated measurement with improved reproducibility. 2. Develop quantitative OCT angiography of the ONH. Three dimensional (3D) OCT angiography has been made practical (3x3 mm scan in 3 seconds) by a novel split-spectrum amplitude-decorrelation algorithm. Preliminary results showed dramatic loss of ONH microcirculation in early glaucoma. Algorithmic improvement in angiography, segmentation, quantification, and automation are planned. 3. Measure nerve structure from the ONH to retinal ganglion cells. By registering several volumetric scans, we have demonstrated complete 3D characterization of the retinal fiber pathway from the ONH to the macula. Fully automated quantification of these structures will be developed. 4. Evaluate advanced OCT technologies in clinical studies. The utility of functional and structural OCT in glaucoma will be evaluated in a longitudinal observational study of 150 glaucoma and healthy subjects. The effect of IOP-lowering surgery on blood flow will be studied in 40 subjects. Retinal blood flow, ONH circulation, optic disc rim volume, peripapillary nerve fiber layer volume, and macular ganglion cell complex volume are all pieces of the same glaucoma puzzle. This project will develop novel imaging methods that allow us to look at the whole picture using one tool - ultrahigh-speed OCT.