使用标准SD-OCT器械在临床环境中客观评估角膜透明度
Objective assessment of corneal transparency in the clinical setting with standard SD-OCT devices
摘要：
目得：开发一种自动算法，从临床光谱域OCT图像中提取定量角膜透明度参数。建立健康角膜标准透明度值的代表性数据集。方法：来自标准临床设备（RTVue-XR Avanti，Optovue Inc.）的83例正常角膜（年龄22-50岁）的SD-OCT图像。被处理了首先应用预处理过程，包括导数方法和基于PCA的校正掩模，以消除常见的中心伪影（即，顶点中心柱饱和伪影和后基质伪影）并实现标准化分析。然后在6 mm宽的角膜区域上提取平均强度基质深度分布，并根据我们先前开发的方法进行分析，该方法导出与组织中的光传播物理学相关的定量透明度参数，特别是组织异质性（Birge比; $B_r$），然后是均匀组织中的光子平均自由程（$l_s$）（即，$B_r \sim 1$）。研究结果：在确认基质同质性（$B_r < 10$，IDR：1.9-5.1）后，我们测量了中位$l_s$为570 $μ$ m（IDR：270-2400 $μ$ m）。考虑到角膜厚度，这可以转化为51 $\%$（IDR：22-83 $\%$）的透射（相干）光$T_{coh(stroma)}$的中值分数。透明度和年龄或厚度之间没有统计学显着的相关性founded. CONCLUSIONS：我们的算法提供了强大的和定量的测量标准的临床SD-OCT图像的角膜透明度。它产生较低的透明度值比以前报道的，这可能是由于我们的方法是专门敏感的空间相干光。排除中心伪影大于300 $μ$ m的图像也将我们的中位$T_{coh(stroma)}$提高到70 $\%$（IDR：34-87 $\%$）。
英文摘要：
PURPOSE: To develop an automated algorithm allowing extraction of quantitative corneal transparency parameters from clinical spectral-domain OCT images. To establish a representative dataset of normative transparency values from healthy corneas. METHODS: SD-OCT images of 83 normal corneas (ages 22-50 years) from a standard clinical device (RTVue-XR Avanti, Optovue Inc.) were processed. A pre-processing procedure is applied first, including a derivative approach and a PCA-based correction mask, to eliminate common central artifacts (i.e., apex-centered column saturation artifact and posterior stromal artifact) and enable standardized analysis. The mean intensity stromal-depth profile is then extracted over a 6-mm-wide corneal area and analyzed according to our previously developed method deriving quantitative transparency parameters related to the physics of light propagation in tissues, notably tissular heterogeneity (Birge ratio; $B_r$), followed by the photon mean-free path ($l_s$) in homogeneous tissues (i.e., $B_r \sim 1$). RESULTS: After confirming stromal homogeneity ($B_r < 10$, IDR: 1.9-5.1), we measured a median $l_s$ of 570 $μ$m (IDR: 270-2400 $μ$m). Considering corneal thicknesses, this may be translated into a median fraction of transmitted (coherent) light $T_{coh(stroma)}$ of 51$\%$ (IDR: 22-83$\%$). No statistically significant correlation between transparency and age or thickness was found. CONCLUSIONS: Our algorithm provides robust and quantitative measurement of corneal transparency from standard clinical SD-OCT images. It yields lower transparency values than previously reported, which may be attributed to our method being exclusively sensitive to spatially coherent light. Excluding images with central artifacts wider than 300 $μ$m also raises our median $T_{coh(stroma)}$ to 70$\%$ (IDR: 34-87$\%$).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
