Institute of Biomedical Engineering, University of Montréal, Montréal, Canada.
Research Center, CHU Sainte-Justine, Montréal, Canada.
Invest Ophthalmol Vis Sci. 2021 Oct 4;62(13):20. doi: 10.1167/iovs.62.13.20.
The purpose of this study was to develop an in vivo optical coherence tomography (OCT) system capable of imaging the developing mouse retina and its associated morphometric and microstructural changes.
Thirty-four wild-type mice (129S1/SvlmJ) were anesthetized and imaged between postnatal (P) day 7 and P21. OCT instrumentation was developed to optimize signal intensity and image quality. Semi-automatic segmentation tools were developed to quantify the retinal thickness of the nerve fiber layer (NFL), inner plexiform layer (IPL), inner nuclear layer (INL), and the outer retinal layers (ORL), in addition to the total retina. The retinal maturation was characterized by comparing layer thicknesses between consecutive time points.
From P7 to P10, the IPL increased significantly, consistent with retinal synaptogenesis. From P10 to P12, the IPL and ORL also increased, which is coherent with synaptic connectivity and photoreceptor maturation. In contrast, during these periods, the INL decreased significantly, consistent with cellular densification and selective apoptotic "pruning" of the tissue during nuclear migration. Thereafter from P12 to P21, the INL continued to thin (significantly from P17 to P21) whereas the other layers remained unchanged. No time-dependent changes were observed in the NFL. Overall, changes in the total retina were attributed to those in the IPL, INL, and ORL. Regions of the retina adjacent to the optic nerve head were thinner than distal regions during maturation.
Changes in retinal layer thickness are consistent with retinal developmental mechanisms. Accordingly, this report opens new horizons in using our system in the mouse to characterize longitudinally developmental digressions in models of human diseases.
本研究旨在开发一种可用于对发育中的小鼠视网膜及其相关形态和微观结构变化进行成像的体内光学相干断层扫描（OCT）系统。
34 只野生型小鼠（129S1/SvlmJ）麻醉后，在出生后（P）第 7 天至 P21 天进行成像。开发了 OCT 仪器，以优化信号强度和图像质量。开发了半自动分割工具，以定量测量神经纤维层（NFL）、内丛状层（IPL）、内核层（INL）和外视网膜层（ORL）的视网膜厚度，以及总视网膜厚度。通过比较连续时间点的层厚度来描述视网膜成熟度。
从 P7 到 P10，IPL 显著增加，与视网膜突触发生一致。从 P10 到 P12，IPL 和 ORL 也增加，这与突触连接和光感受器成熟一致。相比之下，在此期间，INL 显著减少，与核迁移过程中的细胞密集化和选择性凋亡“修剪”一致。此后，从 P12 到 P21，INL 继续变薄（从 P17 到 P21 显著变薄），而其他层保持不变。在 NFL 中未观察到与时间相关的变化。总的来说，总视网膜的变化归因于 IPL、INL 和 ORL 的变化。在成熟过程中，视神经头部附近的视网膜区域比远端区域薄。
视网膜层厚度的变化与视网膜发育机制一致。因此，本报告为在小鼠中使用我们的系统来表征人类疾病模型中的纵向发育偏差开辟了新的视野。
