Measurement and imaging of birefringent properties of the human cornea with phase-resolved, polarization-sensitive optical coherence tomography
Measurement and imaging of birefringent properties of the human cornea with phase-resolved, polarization-sensitive optical coherence tomography
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DOI：
10.1117/1.1629308
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发表时间：
2004-01-01
影响因子：
3.5
通讯作者：
Hitzenberger, CK
中科院分区：
文献类型：
--
作者：
Götzinger, E;Pircher, M;Hitzenberger, CK
光学相干层析成像（OCT）是一种新兴的技术，用于透明和散射介质的高分辨率，非接触成像。偏振敏感光学相干断层扫描（PS-OCT）是OCT的功能扩展，其可以对生物样品的双折射性质进行成像。利用PS-OCT对离体人角膜的延迟和双折射轴方向进行测量和成像。我们使用了一个双通道PS-OCT系统，采用相敏记录的干涉信号在两个正交的偏振通道。使用基于希尔伯特变换的算法，可以计算每个横向测量位置仅用单个A扫描的样品的延迟和慢轴取向。虽然延迟信息被编码在两个干涉信号的振幅比中，但是轴取向完全被编码在它们的相位差中。我们目前的地图延迟和分布的慢轴方向的人角膜的纵向横截面和正面图像获得的后表面的角膜。延迟在径向方向上和深度增加;慢轴在横向方向上变化。角膜的延迟和慢轴分布的知识可能会改善青光眼诊断的神经纤维偏振测定，并可能有助于诊断不同类型的角膜病理。(C)2004年，美国光电仪器工程师学会。
Optical coherence tomography (OCT) is an emerging technology for high-resolution, noncontact imaging of transparent and scattering media. Polarization-sensitive optical coherence tomography (PS-OCT) is a functional extension of OCT that can image birefringent properties of a biological sample. PS-OCT was used to measure and image retardation and birefringent axis orientation of in vitro human cornea. We used a two-channel PS-OCT system employing a phase-sensitive recording of the interferometric signals in two orthogonal polarization channels. Using an algorithm based on a Hilbert transform, it is possible to calculate the retardation and the slow axis orientation of the sample with only a single A-scan per transversal measurement location. While the retardation information is encoded in the amplitude ratio of the two interferometric signals, the axis orientation is encoded entirely in their phase difference. We present maps of retardation and the distribution of slow axis orientation of the human cornea in longitudinal cross-sections and en face images obtained at the back surface of the cornea. The retardation increases in a radial direction and with depth; the slow axis varies in the transversal direction. Knowledge of the retardation and the slow axis distribution of the cornea might improve nerve fiber polarimetry for glaucoma diagnostics and could be useful for diagnosing different types of pathologies of the cornea. (C) 2004 Society of Photo-Optical Instrumentation Engineers.