Sensitivity and specificity of posterior corneal elevation measured by Pentacam in discriminating keratoconus/subclinical keratoconus
Sensitivity and specificity of posterior corneal elevation measured by Pentacam in discriminating keratoconus/subclinical keratoconus
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DOI：
10.1016/j.ophtha.2008.02.020
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发表时间：
2008-09-01
期刊：
影响因子：
13.7
通讯作者：
Grignolo, Federico M.
中科院分区：
文献类型：
--
作者：
de Sanctis, Ugo;Loiacono, Carlotta;Grignolo, Federico M.
目的：目的：评价后提升术在区分圆锥角膜和亚临床圆锥角膜与正常角膜中的敏感性和特异性。设计：前瞻性病例对照研究。参与者：75例圆锥角膜患者，25例亚临床圆锥角膜患者，64例正常角膜的屈光手术候选者。方法：在每个患者的一只眼睛中，使用Pentacam旋转Scheimpflug相机（Oculus，韦茨拉尔，德国）在中央5 mm处测量后角膜抬高。在单独的分析中，将圆锥角膜和圆锥角膜下的后角膜抬高与正常角膜进行比较。受试者工作特征（ROC）曲线用于确定测试的总体预测准确性（曲线下面积），并确定最佳的后角膜抬高截止点，以最大限度地提高区分圆锥角膜和正常角膜下圆锥角膜的灵敏度和特异性。Logistic回归用于支持通过ROC曲线分析确定的截止点，并检查模型的有效性;模型拟合优度使用r（2）估计，其内部验证通过bootstrapping分析。主要结果测量：圆锥角膜、圆锥角膜下和正常角膜的后角膜抬高。圆锥角膜的平均后角膜高度在统计学上更高（100.7 ± 49.2 μ m; P
Purpose: To estimate the sensitivity and specificity of posterior elevation in discriminating keratoconus and subclinical keratoconus from normal corneas.Design: Prospective case-control study.Participants: Seventy-five patients with keratoconus, 25 with subclinical keratoconus, and 64 refractive surgery candidates with normal corneas.Methods: In one eye of each patient, posterior corneal elevation was measured in the central 5 mm using the Pentacam rotating Scheimpflug camera (Oculus, Wetzlar, Germany). Posterior corneal elevation in keratoconus and subdinical keratoconus were compared with that in normal corneas in separate analyses. Receiver operating characteristic (ROC) curves were used to determine the test's overall predictive accuracy (area under the curve) and to identify optimal posterior corneal elevation cutoff points to maximize sensitivity and specificity in discriminating keratoconus and subdinical keratoconus from normal corneas. Logistic regression was used to support cutoff points identified through ROC curve analysis, and to check for model validity; model goodness-of-fit was estimated using r(2), and its internal validation was by bootstrapping analysis.Main Outcome Measures: Posterior corneal elevation in keratoconus, subdinical keratoconus, and normal corneas.Results: Mean posterior corneal elevation was statistically higher in keratoconus (100.7 +/- 49.2 mu m; P