Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada.
Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.
Invest Ophthalmol Vis Sci. 2019 Apr 1;60(5):1556-1565. doi: 10.1167/iovs.18-26441.
We implemented optical coherence tomography angiography (OCT-A) in mice to: (1) develop quantitative parameters from OCT-A images, (2) measure the reproducibility of the parameters, and (3) determine the impact of experimental models of inner and outer retinal damage on OCT-A findings.
OCT-A images were acquired with a customized system (Spectralis Multiline OCT2). To assess reproducibility, imaging was performed five times over 1 month. Inner retinal damage was induced with optic nerve transection, crush, or intravitreal N-methyl-d-aspartic acid injection in transgenic mice with fluorescently labeled retinal ganglion cells (RGCs). Light-induced retinal damage was induced in albino mice. Mice were imaged at baseline and serially post injury. Perfusion density, vessel length, and branch points were computed from OCT-A images of the superficial, intermediate, and deep vascular plexuses.
The range of relative differences measured between sessions across the vascular plexuses were: perfusion density (2.8%-7.0%), vessel length (1.9%-4.1%), and branch points (1.9%-5.0%). In mice with progressive RGC loss, imaged serially and culminating in around 70% loss in the fluorescence signal and 18% loss in inner retinal thickness, there were no measurable changes in any OCT-A parameter up to 4 months post injury that exceeded measurement variability. However, light-induced retinal damage elicited a progressive loss of the deep vascular plexus signal, starting as early as 3 days post injury.
Vessel length and branch points were generally the most reproducible among the parameters. Injury causing RGC loss in mice did not elicit an early change in the OCT-A signal.
我们在小鼠中实施光相干断层扫描血管造影术（OCT-A）以：（1）从 OCT-A 图像中得出定量参数，（2）测量参数的可重复性，以及（3）确定内、外视网膜损伤的实验模型对 OCT-A 结果的影响。
使用定制系统（Spectralis Multiline OCT2）获取 OCT-A 图像。为了评估可重复性，在 1 个月内进行了 5 次成像。通过视神经横断、压碎或玻璃体内注射 N-甲基-D-天冬氨酸在荧光标记的视网膜神经节细胞（RGC）转基因小鼠中诱导内视网膜损伤。在白化小鼠中诱导光诱导的视网膜损伤。在基线和损伤后连续对小鼠进行成像。从浅层、中层和深层血管丛的 OCT-A 图像中计算灌注密度、血管长度和分支点。
在血管丛中各次测量之间测量的相对差异范围为：灌注密度（2.8%-7.0%）、血管长度（1.9%-4.1%）和分支点（1.9%-5.0%）。在 RGC 逐渐丢失的小鼠中，进行了连续成像，最终荧光信号丢失约 70%，内视网膜厚度丢失 18%，在损伤后 4 个月内，任何 OCT-A 参数都没有发生可测量的变化，这些变化超过了测量的变异性。然而，光诱导的视网膜损伤引起深层血管丛信号的进行性丧失，早在损伤后 3 天即可出现。
在这些参数中，血管长度和分支点通常最具可重复性。在小鼠中引起 RGC 丢失的损伤不会引起 OCT-A 信号的早期变化。
