Tan Jinzhen, Qiu Rui, Ding Xueqing, Dai Cuixia, Meng Jing, Zhao Jingxiu, Ma Fei, Qi Sumin
School of Computer, Qufu Normal University, Rizhao, China.
College of Science, Shanghai Institute of Technology, Shanghai, China.
J Biophotonics. 2022 Dec;15(12):e202200146. doi: 10.1002/jbio.202200146. Epub 2022 Sep 18.
Optical coherence tomography (OCT) is an imaging modality that acquires high-resolution cross-sectional images of living tissues and it has become the standard in ophthalmological diagnoses. However, most quantitative morphological measurements are based on the raw OCT images which are distorted by several mechanisms such as the refraction of probe light in the sample and the scan geometries and thus the analysis of the raw OCT images inevitably induced calculation errors. In this paper, based on Fermat's principle and the concept of inverse light tracing, image distortions due to refraction occurred at tissue boundaries in the whole-eye OCT imaging of mouse by telecentric scanning were corrected. Specially, the mathematical correction models were deducted for each interface, and the high-precision whole-eye image was recovered segment by segment. We conducted phantom and in vivo experiments on mouse and human eyes to verify the distortion correction algorithm, and several parameters of the radius of curvature, thickness of tissues and error, were calculated to quantitatively evaluate the images. Experimental results demonstrated that the method can provide accurate and reliable measurements of whole-eye parameters and thus be a valuable tool for the research and clinical diagnosis.
光学相干断层扫描（OCT）是一种成像方式，可获取活体组织的高分辨率横截面图像，已成为眼科诊断的标准方法。然而，大多数定量形态学测量基于原始OCT图像，这些图像会因多种机制而失真，如样品中探测光的折射和扫描几何形状等，因此对原始OCT图像的分析不可避免地会产生计算误差。本文基于费马原理和逆光追迹概念，对小鼠全眼OCT成像中因远心扫描在组织边界处发生折射而导致的图像失真进行了校正。具体而言，为每个界面推导了数学校正模型，并逐段恢复了高精度的全眼图像。我们对小鼠和人眼进行了模型实验和体内实验，以验证失真校正算法，并计算了曲率半径、组织厚度和误差等几个参数，以定量评估图像。实验结果表明，该方法能够提供准确可靠的全眼参数测量，从而成为研究和临床诊断的有价值工具。
