Leahy Conor, Radhakrishnan Harsha, Weiner Geoffrey, Goldberg Jeffrey L, Srinivasan Vivek J
Department of Biomedical Engineering, University of California Davis, Davis, California, United States.
Shiley Eye Institute, University of California San Diego, San Diego, California, United States.
Invest Ophthalmol Vis Sci. 2015 Sep;56(10):5785-93. doi: 10.1167/iovs.15-17210.
The purpose of this study is to demonstrate three-dimensional (3D) graphing based on optical coherence tomography (OCT) angiography for characterization of the inner retinal vascular architecture and determination of its topologic principles.
Rat eyes (N = 3) were imaged with a 1300-nm spectral/Fourier domain OCT microscope. A topologic model of the inner retinal vascular network was obtained from OCT angiography data using a combination of automated and manually-guided image processing techniques. Using a resistive network model, with experimentally-quantified flow in major retinal vessels near the optic nerve head as boundary conditions, theoretical changes in the distribution of flow induced by vessel dilations were inferred.
A topologically-representative 3D vectorized graph of the inner retinal vasculature, derived from OCT angiography data, is presented. The laminar and compartmental connectivity of the vasculature are characterized. In contrast to sparse connectivity between the superficial vitreal vasculature and capillary plexuses of the inner retina, connectivity between the two capillary plexus layers is dense. Simulated dilation of single arterioles is shown to produce both localized and lamina-specific changes in blood flow, while dilation of capillaries in a given retinal vascular layer is shown to lead to increased total flow in that layer.
Our graphing and modeling data suggest that vascular architecture enables both local and lamina-specific control of blood flow in the inner retina. The imaging, graph analysis, and modeling approach presented here will help provide a detailed characterization of vascular changes in a variety of retinal diseases, both in experimental preclinical models and human subjects.
本研究旨在展示基于光学相干断层扫描血管造影（OCTA）的三维（3D）绘图，以表征视网膜内层血管结构并确定其拓扑原理。
用1300纳米光谱/傅里叶域OCT显微镜对大鼠眼睛（N = 3）进行成像。使用自动和手动引导的图像处理技术相结合的方法，从OCTA数据中获得视网膜内层血管网络的拓扑模型。以视神经乳头附近主要视网膜血管中经实验量化的血流作为边界条件，使用电阻网络模型推断血管扩张引起的血流分布的理论变化。
展示了从OCTA数据得出的视网膜内层脉管系统的拓扑代表性3D矢量化图。对脉管系统的层状和分区连通性进行了表征。与表层玻璃体脉管系统和视网膜内层毛细血管丛之间的稀疏连通性相比，两个毛细血管丛层之间的连通性是密集的。模拟单个小动脉的扩张会导致血流产生局部和特定层的变化，而给定视网膜血管层中毛细血管的扩张会导致该层总血流量增加。
我们的绘图和建模数据表明，血管结构能够对视网膜内层的血流进行局部和特定层的控制。本文介绍的成像、图形分析和建模方法将有助于详细表征各种视网膜疾病（包括实验性临床前模型和人类受试者）中的血管变化。
