University of Washington, Department of Bioengineering, Seattle, Washington, United States.
University of Washington, Department of Ophthalmology, Seattle, Washington, United States.
J Biomed Opt. 2024 Jul;29(7):076008. doi: 10.1117/1.JBO.29.7.076008. Epub 2024 Jul 27.
The iStent is a popular device designed for glaucoma treatment, functioning by creating an artificial fluid pathway in the trabecular meshwork (TM) to drain aqueous humor. The assessment of iStent implantation surgery is clinically important. However, current tools offer limited information.
We aim to develop innovative assessment strategies for iStent implantation using optical coherence tomography (OCT) to evaluate the position and orientation of the iStent and its biomechanical impact on outflow system dynamics.
We examined four iStents in the two eyes of a glaucoma patient. Three-dimensional (3D) OCT structural imaging was conducted for each iStent, and a semi-automated algorithm was developed for iStent segmentation and visualization, allowing precise measurement of position and orientation. In addition, phase-sensitive OCT (PhS-OCT) imaging was introduced to measure the biomechanical impact of the iStent on the outflow system quantified by cumulative displacement (CDisp) of pulse-dependent trabecular TM motion.
The 3D structural image processed by our algorithm definitively resolved the position and orientation of the iStent in the anterior segment, revealing substantial variations in relevant parameters. PhS-OCT imaging demonstrated significantly higher CDisp in the regions between two iStents compared to locations distant from the iStents in both OD ( ) and OS ( ).
Our proposed structural imaging technique improved the characterization of the iStent's placement. The imaging results revealed inherent challenges in achieving precise control of iStent insertion. Furthermore, PhS-OCT imaging unveiled potential biomechanical alterations induced by the iStent. This unique methodology shows potential as a valuable clinical tool for evaluating iStent implantation.
iStent 是一种用于治疗青光眼的流行设备，通过在小梁网（TM）中创建人工液体通道来排出房水。评估 iStent 植入手术在临床上很重要。然而，目前的工具提供的信息有限。
我们旨在使用光学相干断层扫描（OCT）为 iStent 植入开发创新的评估策略，以评估 iStent 的位置和方向及其对流出系统动力学的生物力学影响。
我们检查了一名青光眼患者的两只眼睛中的四个 iStents。对每个 iStent 进行了三维（3D）OCT 结构成像，并开发了一种半自动化算法用于 iStent 分割和可视化，从而可以精确测量位置和方向。此外，引入了相敏 OCT（PhS-OCT）成像来测量 iStent 对流出系统的生物力学影响，通过脉冲相关小梁 TM 运动的累积位移（CDisp）来量化。
我们的算法处理的 3D 结构图像明确解决了前段中 iStent 的位置和方向问题，显示出相关参数的显着变化。PhS-OCT 成像显示，与远离 iStent 的位置相比，两个 iStent 之间的区域的 CDisp 在 OD（ ）和 OS（ ）中显着更高。
我们提出的结构成像技术改善了 iStent 放置的特征描述。成像结果揭示了实现 iStent 插入精确控制的固有挑战。此外，PhS-OCT 成像揭示了 iStent 引起的潜在生物力学改变。这种独特的方法显示出作为评估 iStent 植入的有价值的临床工具的潜力。
