From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile.
From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile.
Am J Ophthalmol. 2021 Jun;226:235-242. doi: 10.1016/j.ajo.2021.01.012. Epub 2021 Jan 30.
PURPOSE: To evaluate Pentacam and OPD-Scan parameters in the early detection of keratoconus.
Retrospective case-control study.
Case group included 50 clinically unaffected fellow eyes diagnosed with asymmetric keratoconus showing subtle qualitative changes at the 0.5-D sensitivity OPD-Scan scale, as well as normal anterior and back elevation difference map at Belin/Ambrósio enhanced ectasia display (BAD) at the Pentacam. Control group included 172 normal eyes that underwent Lasik surgery and presented no complications throughout the 2-year follow-up period. OPD-Scan and Pentacam parameters were compared, calculating sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). A multivariate analysis was performed using Pentacam or OPD-Scan variables, and a model using variables of both devices.
Pentacam variables with AUC ≥0.8 were keratoconus index (0.85), index of height decentration (0.81), and overall deviation at BAD (0.8). OPD-Scan variables with AUC ≥0.8 were keratoconus prediction index (0.83), surface asymmetry index (0.83), and total of higher-order trefoil aberration (0.8). In the multivariate analysis, the AUC was 0.85 in the case of OPD-Scan whereas it was 0.89 in the case of Pentacam. When combining all variables from the 2 devices, the AUC was 0.93, with a sensitivity of 82% and a specificity of 94%.
Several parameters of OPD-Scan and Pentacam can be useful to differentiate cases from normal control eyes, demonstrating even better results when combining parameters of both devices. Anterior corneal indexes were the most important parameters to discriminate both groups.
目的：评估 Pentacam 和 OPD-Scan 参数在早期发现圆锥角膜中的作用。
回顾性病例对照研究。
病例组包括 50 只临床无异常的对侧眼，这些眼在 0.5-D 敏感度 OPD-Scan 量表上显示出轻微的定性改变，并且在 Belin/Ambrósio 增强扩张显示（BAD）的 Pentacam 上的前、后高度差图正常。对照组包括 172 只接受过 Lasik 手术的正常眼，在 2 年的随访期间没有出现任何并发症。比较了 OPD-Scan 和 Pentacam 参数，计算了敏感性、特异性和接收器操作特性曲线（ROC）下的面积（AUC）。使用 Pentacam 或 OPD-Scan 变量进行了多变量分析，并使用两种设备的变量建立了模型。
AUC≥0.8 的 Pentacam 变量包括圆锥角膜指数（0.85）、高度偏心指数（0.81）和 BAD 的整体偏差（0.8）。AUC≥0.8 的 OPD-Scan 变量包括圆锥角膜预测指数（0.83）、表面不对称指数（0.83）和总高阶三叶像差（0.8）。在多变量分析中，OPD-Scan 的 AUC 为 0.85，而 Pentacam 的 AUC 为 0.89。当结合两种设备的所有变量时，AUC 为 0.93，敏感性为 82%，特异性为 94%。
OPD-Scan 和 Pentacam 的几个参数可用于区分病例和正常对照眼，当结合两种设备的参数时，结果甚至更好。前角膜指数是区分两组的最重要参数。
