ECOS (Clinical Ocular Studies) Laboratory, Buenos Aires, Argentina; Ophthalmology Division, Hospital de Clínicas José de San Martín, University of Buenos Aires, Buenos Aires, Argentina.
ECOS (Clinical Ocular Studies) Laboratory, Buenos Aires, Argentina.
Am J Ophthalmol. 2014 Jul;158(1):32-40.e2. doi: 10.1016/j.ajo.2014.03.018. Epub 2014 Apr 5.
To evaluate Pentacam ectasia detection indices in topographically normal patients and in subclinical keratoconus cases.
Prospective, observational case series.
setting: Institutional. patients: Group 1 comprised 1 eye from 189 patients with unremarkable topography and Groups 2 and 3 included the better and worse eyes, respectively, of 55 keratoconic patients. Group 2 eyes with normal topography (n = 37) were considered subclinical keratoconus cases. observation procedure: Pentacam Scheimpflug tomography. main outcome measures: Eleven Pentacam ectasia detection indices.
All Pentacam ectasia indices significantly differed between Groups 1 and 2 and were correlated with keratoconus grade. Only 99 eyes (52%) in Group 1 had normal values for every index, whereas 7 subclinical keratoconus eyes (19%) showed 2 or fewer abnormal indices. Standardized relational thickness and overall deviation indices had 73% and 89% sensitivity for subclinical keratoconus, respectively. Both average and maximum pachymetric progression indices offered 84% sensitivity while maximum relational thickness index showed 78% sensitivity for subclinical keratoconus. Optimized cutoff values for subclinical keratoconus increased the sensitivity of the standardized and maximum relational thickness indices.
Pentacam Scheimpflug tomography can detect most subclinical keratoconus cases with unremarkable topography, but performance is not as good as reported and varies considerably for each index. The overall deviation, average and maximum pachymetric progression, and maximum relational thickness indices offer the highest sensitivity, which can be improved by using optimized cutoff values. Specificity constitutes an issue for some indices and up to 10% of subclinical keratoconus cases may go undetected by this technology.
评估 Pentacam 角膜膨隆检测指数在角膜地形正常患者和亚临床圆锥角膜病例中的表现。
前瞻性、观察性病例系列。
地点：机构。患者：第 1 组由 189 例角膜地形正常患者的 1 只眼组成，第 2 组和第 3 组分别包括 55 例圆锥角膜患者的较好眼和较差眼。第 2 组具有正常地形的眼睛（n=37）被认为是亚临床圆锥角膜病例。观察程序：Pentacam Scheimpflug 断层扫描。主要观察指标：11 项 Pentacam 角膜膨隆检测指数。
第 1 组和第 2 组之间的所有 Pentacam 角膜膨隆指数均有显著差异，且与圆锥角膜等级相关。第 1 组中仅有 99 只眼（52%）的所有指数均正常，而 7 只亚临床圆锥角膜眼（19%）有 2 项或更少的异常指数。标准化相对厚度和整体偏差指数对亚临床圆锥角膜的敏感性分别为 73%和 89%。平均和最大角膜厚度进展指数对亚临床圆锥角膜的敏感性分别为 84%，最大相对厚度指数的敏感性为 78%。亚临床圆锥角膜的优化截断值提高了标准化和最大相对厚度指数的敏感性。
Pentacam Scheimpflug 断层扫描可以检测大多数具有正常地形的亚临床圆锥角膜病例，但性能不如报道的那样好，且每个指数的性能差异很大。整体偏差、平均和最大角膜厚度进展以及最大相对厚度指数的敏感性最高，通过使用优化的截断值可以提高其敏感性。一些指数的特异性是一个问题，多达 10%的亚临床圆锥角膜病例可能无法被这项技术检测到。
