Keratoconus Diagnosis Using Anterior Segment Polarization-Sensitive Optical Coherence Tomography
Keratoconus Diagnosis Using Anterior Segment Polarization-Sensitive Optical Coherence Tomography
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DOI：
10.1167/iovs.12-10979
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发表时间：
2013-02-01
影响因子：
4.4
通讯作者：
Yasuno, Yoshiaki
中科院分区：
文献类型：
--
作者：
Fukuda, Shinichi;Yamanari, Masahiro;Yasuno, Yoshiaki
目的。应用偏振敏感光学相干断层扫描（PS-OCT）观察角膜圆锥病变和正常角膜的组织特性，并通过受者工作特征曲线下面积（AUROC）和马氏距离分析对早期角膜圆锥病变进行评价。采用PS-OCT和角膜前段(CAS)-OCT对20例圆锥角膜患者的31只眼、7例疑似圆锥角膜患者的7只眼和25例正常人的25只眼进行了观察。测量角膜后表面的平均相位延迟、曲率、视频成像参数、规则和不规则散光、视光图和仰角。计算各参数的AUROC，评价其对圆锥角膜和疑似圆锥角膜的诊断能力。而在正常对照中，面部相位延迟图中心显示低且均匀的双折射，而在角膜斜视中，双折射随疾病严重程度而增加。一些疑似圆锥角膜有明显的高双折射值，但在前表面没有圆锥角膜的形态学征象。正常、疑似圆锥角膜和圆锥角膜患者的相位延迟值分别为0.20 +/- 0.06、0.35 +/- 0.06和0.50 +/- 0.14弧度，6mm直径分别为0.29 +/- 0.22、0.33 +/- 0.13和0.74 +/- 0.45弧度。曲率、影像成像参数、规则散光和不规则散光、海拔高度等外部形态学参数对圆锥角膜与正常对照具有较高的auroc。另一方面，利用马氏距离，反映组织显微结构特征的相延迟AUROC在鉴别疑似圆锥角膜与正常对照方面具有较高的价值（0.989 ~ 1.000）。由于胶原纤维板层结构的改变，圆锥角膜患者角膜后表面的平均面相迟滞增加。视相迟滞是鉴别疑似圆锥角膜的敏感指标，可能有助于早期甚至亚临床圆锥角膜的发现。（Invest Ophthalmol Vis Sci. 2013;54:1384-1391） DOI:10.1167/iovs.12-10979
PURPOSE. To investigate the tissue properties of keratoconic and normal corneas in vivo by using polarization-sensitive optical coherence tomography (PS-OCT), and to evaluate early keratoconus by the area under the receiver operating characteristic curve (AUROC) and Mahalanobis distance analysis.METHODS. Thirty-one eyes of 20 patients with keratoconus, 7 eyes of 7 patients with keratoconus suspect, and 25 eyes of 25 normal subjects were investigated by PS-OCT and corneal and anterior segment (CAS)-OCT. Average of en face phase retardation of the posterior surface of the cornea, curvature, videokeratographic parameters, regular and irregular astigmatism, pachymetry map, and elevation were measured. The AUROC of each parameter was calculated to evaluate the diagnostic power to detect keratoconus and keratoconus suspect.RESULTS. While in normal controls, the center of the en face phase retardation map showed low and homogeneous birefringence, in keratoconic corneas the birefringence increased with disease severity. Some keratoconus suspects had apparent high birefringence values without displaying morphologic signs of keratoconus in the anterior surface. The phase retardation values for normal, keratoconus suspect, and keratoconus subjects were, respectively, 0.20 +/- 0.06, 0.35 +/- 0.06, and 0.50 +/- 0.14 radians in 3 mm diameter and 0.29 +/- 0.22, 0.33 +/- 0.13, and 0.74 +/- 0.45 radians in 6 mm diameter. Outer morphological parameters such as curvature, videokeratographic parameters, regular and irregular astigmatism, and elevation showed high AUROCs for discriminating keratoconus from normal controls. On the other hand, using Mahalanobis distance, the AUROC of phase retardation, which represents microstructural properties of tissue, showed high value (0.989-1.000) for discriminating between keratoconus suspects and normal controls.CONCLUSIONS. Average of en face phase retardation of the posterior surface of the cornea was increased in keratoconus patients due to changes in the lamellar structure of collagen fibers. Phase retardation was sensitive with regard to discriminating keratoconus suspect and might be useful for detecting very early or even subclinical keratoconus. (Invest Ophthalmol Vis Sci. 2013;54:1384-1391) DOI:10.1167/iovs.12-10979