Biological Imaging Center, California Institute of Technology, Pasadena, CA 91125, USA.
Proc Natl Acad Sci U S A. 2013 Aug 27;110(35):14354-9. doi: 10.1073/pnas.1307315110. Epub 2013 Aug 5.
Detailed visualization of microvascular changes in the human retina is clinically limited by the capabilities of angiography imaging, a 2D fundus photograph that requires an intravenous injection of fluorescent dye. Whereas current angiography methods enable visualization of some retinal capillary detail, they do not adequately reveal the choriocapillaris or other microvascular features beneath the retina. We have developed a noninvasive microvascular imaging technique called phase-variance optical coherence tomography (pvOCT), which identifies vasculature three dimensionally through analysis of data acquired with OCT systems. The pvOCT imaging method is not only capable of generating capillary perfusion maps for the retina, but it can also use the 3D capabilities to segment the data in depth to isolate vasculature in different layers of the retina and choroid. This paper demonstrates some of the capabilities of pvOCT imaging of the anterior layers of choroidal vasculature of a healthy normal eye as well as of eyes with geographic atrophy (GA) secondary to age-related macular degeneration. The pvOCT data presented permit digital segmentation to produce 2D depth-resolved images of the retinal vasculature, the choriocapillaris, and the vessels in Sattler's and Haller's layers. Comparisons are presented between en face projections of pvOCT data within the superficial choroid and clinical angiography images for regions of GA. Abnormalities and vascular dropout observed within the choriocapillaris for pvOCT are compared with regional GA progression. The capability of pvOCT imaging of the microvasculature of the choriocapillaris and the anterior choroidal vasculature has the potential to become a unique tool to evaluate therapies and understand the underlying mechanisms of age-related macular degeneration progression.
详细观察人类视网膜微血管的变化在临床上受到血管造影成像能力的限制，这种二维眼底照片需要静脉注射荧光染料。虽然目前的血管造影方法可以观察到一些视网膜毛细血管的细节，但它们不能充分显示脉络膜毛细血管或视网膜下的其他微血管特征。我们开发了一种非侵入性微血管成像技术，称为相移光学相干断层扫描（pvOCT），它通过分析 OCT 系统获取的数据来三维识别血管。pvOCT 成像方法不仅能够生成视网膜毛细血管灌注图，还可以利用其 3D 能力对数据进行深度分割，以分离视网膜和脉络膜不同层中的血管。本文展示了 pvOCT 对健康正常眼和年龄相关性黄斑变性继发的地图状萎缩（GA）眼的脉络膜前层血管的一些成像能力。所呈现的 pvOCT 数据允许数字分割，以产生视网膜血管、脉络膜毛细血管和 Sattler 层和 Haller 层血管的 2D 深度分辨图像。在 GA 区域内，对浅层脉络膜内 pvOCT 数据的共面投影与临床血管造影图像进行了比较。与区域 GA 进展相比，pvOCT 观察到的脉络膜毛细血管中的异常和血管缺失。pvOCT 对脉络膜毛细血管和前脉络膜血管的微血管成像能力有可能成为评估治疗方法和了解年龄相关性黄斑变性进展潜在机制的独特工具。
