Institute of Biomedical Engineering, College of Medicine and Engineering, National Taiwan University, Taipei, Taiwan.
J Cataract Refract Surg. 2013 May;39(5):779-88. doi: 10.1016/j.jcrs.2012.11.036.
To evaluate the efficacy of using forward second harmonic generation (SHG) and 2-dimensional fast Fourier-transform (2D-FFT) analysis for the label-free characterization and quantification of morphologic changes in the corneal stroma after collagen crosslinking (CXL).
Department of Physics, National Taiwan University, Taipei, Taiwan.
Experimental study.
En face forward SHG imaging and 2D-FFT analysis were performed on ex vivo porcine corneas at the depths of 100, 200, 400, and 800 μm. Morphologic changes in stromal collagen fiber in control, ultraviolet-A (UVA), riboflavin, and riboflavin-UVA treated porcine corneas were assessed. Hematoxylin-eosin staining and Sirius red staining were performed for comparison.
Corneas after CXL treatment tended to have collagen fibers that were wavy compared with the linear pattern in normal corneas. Quantitative 2D-FFT analysis of forward SHG images also showed an increase in the standard deviations of the distribution of stromal collagen fiber orientations, which is indicative of the changed pattern of crosslinked stromal collagen fibers.
Second harmonic generation imaging showed the morphologic changes in stromal collagen after CXL treatment. The linear collagen fibers in normal corneal stroma became wavy after treatment. With the introduction of 2D-FFT analysis, the morphologic changes can be quantified.
评估使用正向二次谐波产生（SHG）和二维快速傅里叶变换（2D-FFT）分析对胶原交联（CXL）后角膜基质的形态变化进行无标记特征描述和定量的效果。
台湾大学物理系，台北，台湾。
实验研究。
对离体猪眼角膜的 100、200、400 和 800μm 深度进行共聚焦前向 SHG 成像和 2D-FFT 分析。评估对照、紫外线-A（UVA）、核黄素和核黄素-UVA 处理的猪眼角膜基质胶原纤维的形态变化。进行苏木精-伊红染色和 Sirius 红染色进行比较。
CXL 治疗后的角膜与正常角膜中的线性胶原纤维相比，其胶原纤维呈现波浪状。来自共聚焦 SHG 图像的 2D-FFT 分析还显示出基质胶原纤维取向分布的标准偏差增加，这表明交联基质胶原纤维的模式发生了变化。
二次谐波产生成像显示了 CXL 治疗后基质胶原的形态变化。正常角膜基质中的线性胶原纤维在治疗后变得波浪状。通过引入 2D-FFT 分析，可以对形态变化进行定量。
