Optical distortion correction in Optical Coherence Tomography for quantitative ocular anterior segment by three-dimensional imaging
Optical distortion correction in Optical Coherence Tomography for quantitative ocular anterior segment by three-dimensional imaging
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DOI：
10.1364/oe.18.002782
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发表时间：
2010-02-01
期刊：
影响因子：
3.8
通讯作者：
Marcos, Susana
中科院分区：
文献类型：
--
作者：
Ortiz, Sergio;Siedlecki, Damian;Marcos, Susana
提出了一种对眼前节光学相干层析成像(OCT)图像进行三维光学变形(折射)校正的方法。该方法包括通过不同曲面的三维射线跟踪、去噪、曲面分割、曲面的Delaunay表示和扇形变形校正。该校正已在理论上应用于真实的计算机眼睛模型，并实验应用于由两个OCT实验室设置(时间域和光谱)获得的具有聚甲基丙烯酸甲酯(PMMA)角膜和人工晶状体(IOL)的假眼、猪眼和活体人眼的OCT图像。根据曲面曲率半径和非球面度对数据进行分析。建立表面参考值之间的比较(计算机模型中的标称值；假眼的非接触式轮廓测量；活体和体外的真眼的Scheimpflg成像)。在应用2-D光学校正和3-D光学校正(在所有情况下都是在扇形失真校正之后)之后，按照传统的用折射率划分光路的方法对OCT数据的结果进行分析。与传统的OCT图像分析方法相比，三维光学失真校正的应用大大提高了曲率半径估计的精度，特别是表面的非球面度。我们发现，由三维光学失真校正的OCT图像得到的曲率半径估计值与标称值的偏差小于1%。3-D光学失真校正对于OCT眼前节成像的定量分析是至关重要的，并且可以精确地获得眼睛内表面的地形。(C)2010年美国光学学会
A method for three-dimensional 3-D optical distortion (refraction) correction on anterior segment Optical Coherence Tomography (OCT) images has been developed. The method consists of 3-D ray tracing through the different surfaces, following denoising, segmentation of the surfaces, Delaunay representation of the surfaces, and application of fan distortion correction. The correction has been applied theoretically to realistic computer eye models, and experimentally to OCT images of: an artificial eye with a Polymethyl Methacrylate (PMMA) cornea and an intraocular lens (IOL), an enucleated porcine eye, and a human eye in vivo obtained from two OCT laboratory set-ups (time domain and spectral). Data are analyzed in terms of surface radii of curvature and asphericity. Comparisons are established between the reference values for the surfaces (nominal values in the computer model; non-contact profilometric measurements for the artificial eye; Scheimpflug imaging for the real eyes in vivo and vitro). The results from the OCT data were analyzed following the conventional approach of dividing the optical path by the refractive index, after application of 2-D optical correction, and 3-D optical correction (in all cases after fan distortion correction). The application of 3-D optical distortion correction increased significantly both the accuracy of the radius of curvature estimates and particularly asphericity of the surfaces, with respect to conventional methods of OCT image analysis. We found that the discrepancies of the radii of curvature estimates from 3-D optical distortion corrected OCT images are less than 1% with respect to nominal values. Optical distortion correction in 3-D is critical for quantitative analysis of OCT anterior segment imaging, and allows accurate topography of the internal surfaces of the eye. (C) 2010 Optical Society of America