Fourier Analysis on Irregular Corneal Astigmatism Using Optical Coherence Tomography in Various Severity Stages of Keratoconus
Fourier Analysis on Irregular Corneal Astigmatism Using Optical Coherence Tomography in Various Severity Stages of Keratoconus
复制标题
使用光学相干断层扫描对圆锥角膜不同严重程度阶段的不规则角膜散光进行傅里叶分析
DOI：
10.1016/j.ajo.2022.07.002
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Kohji Nishida
中科院分区：
文献类型：
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作者：
Sayo Maeno;Shizuka Koh;Ryota Inoue;Yoshinori Oie;Naoyuki Maeda;Vishal Jhanji;Kohji Nishida
目的探讨傅立叶指数对临床或亚临床圆锥角膜（KC）的诊断价值。方法前瞻性横断面研究（50名无任何角膜瘢痕的KC，50名有角膜前瘢痕的KC，26名有角膜后瘢痕且有急性角膜水肿病史的KC），50名有局部KC角膜地形图检查组（50例，无临床症状）、角膜地形图检查前（50例，无临床症状）和对照组（50例）。傅立叶分析将角膜前后表面的屈光数据分解为球面、规则散光、不对称和高阶不规则分量。在对不规则角膜散光进行定量傅立叶分析后，评估了术前角膜地形图、角膜地形图和临床角膜地形图的傅立叶指数与对照眼的区分能力。（两者P<0.001），接受者工作特征曲线（AUROC）下的最大面积分别为0.778和0.709。地形KC的前部不对称、后部不对称和后部高阶不规则分量也是如此（AUROC分别为0.945、0.941和0.893），而临床KC中所有傅立叶分量的AUROC均>0.948。结论使用OCT的散光分析可以评估各种KC阶段的前后角膜不规则散光，从非常轻度到晚期，包括角膜瘢痕的严重病例。角膜后表面的不规则散光指数在区分早期KC阶段中显示出最高的AUROC值。
PURPOSETo investigate the diagnostic capability of Fourier indices in detecting clinical or subclinical keratoconus (KC).DESIGNProspective cross-sectional study.METHODSThe study included 126 eyes with clinical KC (50 KC without any corneal scar, 50 KC with anterior corneal scar, and 26 KC with posterior scar having a history of acute corneal hydrops), 50 with topographic KC (without clinical signs), 50 with pre-topographic KC (normal topography without clinical signs), and 50 controls.Corneal tomographic data were obtained using anterior segment optical coherence tomography (OCT). Fourier analysis decomposed dioptric data from both anterior and posterior corneal surface into spherical, regular astigmatism, asymmetry, and higher-order irregularity components. The discriminating ability of the Fourier indices of pre-topographic KC, topographic KC, and clinical KC from controls were assessed after quantitative Fourier analysis of irregular corneal astigmatism.RESULTSPosterior asymmetry and higher-order irregularity components were significantly greater in pre-topographic KC eyes than those in controls (P< .001 for both), with the highest area under the receiver operating characteristic curve (AUROC) of 0.778 and 0.709, respectively. The same was true for anterior asymmetry, posterior asymmetry, and posterior higher-order irregularity components in topographic KC (AUROC of 0.945, 0.941, and 0.893, respectively), whereas it was >0.948 for all Fourier components in clinical KC.CONCLUSIONSFourier analysis using OCT can evaluate anterior and posterior corneal irregular astigmatism of various KC stages, from very mild to advanced, including severe cases with corneal scar. Irregular astigmatism indices from the posterior corneal surface showed the highest AUROC values in discriminating early KC stages.