School of Medical Imaging, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China.
School of Biomedical Engineering, Beijing Key Laboratory of Fundamental Research On Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China.
Med Biol Eng Comput. 2022 Jul;60(7):1915-1927. doi: 10.1007/s11517-022-02580-6. Epub 2022 May 6.
Elevated intraocular pressure (IOP) appears to have a broader impact on increased resistance to aqueous humor (AH) outflow through the conventional aqueous outflow system (AOS). However, it is still unknown how AH drainage resistance is produced or why it becomes increased in glaucoma. It is hard to accurately obtain hydrodynamic parameters of AH within the trabecular meshwork (TM) outflow pathway tissues based on current technology. In this study, we reconstructed the rat AOS model with high-resolution two-photon imaging, and simulated the AH outflow process. The resolution of the two-photon imaging system can be up to 0.5 μm for imaging the AOS tissues. Quite a few morphological parameters of rat TM in conditions of normal and elevated IOP were determined using the experiment integrated with the simulation method. We determined that the TM thickness is 49.51 ± 6.07 μm with an IOP of 5.32 kPa, which significantly differed from the TM thickness of 66.4 ± 5.14 μm in the normal IOP group. Furthermore, 3D reconstruction of local aqueous drainage channels from two-photon microscopy images revealed detailed structures of the AOS and permitted the identification of 3D relationships of Schlemm's canal, collector channel, and trabecular drainage channels. An algorithm of finite element micro-modeling of the rat TM outflow pathways reveals the importance of TM for mechanical performance, with the potential to assist clinical therapies for glaucoma that seek to steer clear of an abnormal TM.
眼内压（IOP）升高似乎对通过传统房水流出系统（AOS）增加房水（AH）流出阻力有更广泛的影响。然而，目前尚不清楚 AH 引流阻力是如何产生的，也不知道为什么青光眼会导致其增加。根据目前的技术，很难准确获得小梁网（TM）流出途径组织内的 AH 流体动力学参数。在这项研究中，我们使用高分辨率双光子成像重建了大鼠 AOS 模型，并模拟了 AH 流出过程。双光子成像系统的分辨率可达 0.5 μm，可用于成像 AOS 组织。我们通过实验与模拟相结合的方法，确定了正常和升高 IOP 条件下大鼠 TM 的许多形态学参数。我们确定在 IOP 为 5.32 kPa 时 TM 的厚度为 49.51 ± 6.07 μm，与正常 IOP 组中 66.4 ± 5.14 μm 的 TM 厚度有显著差异。此外，从双光子显微镜图像对局部房水排水通道的 3D 重建揭示了 AOS 的详细结构，并允许识别施莱姆氏管、收集管和小梁排水通道的 3D 关系。大鼠 TM 流出途径的有限元微模型算法揭示了 TM 对机械性能的重要性，这可能有助于为避免异常 TM 的青光眼临床治疗提供指导。
