Steinberg Johannes, Katz Toam, Lücke Kristina, Frings Andreas, Druchkiv Vasyl, Linke Stephan J
*Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; †zentrumsehstärke, Hamburg, Germany; and ‡Care-Vision Germany, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Cornea. 2015 Nov;34(11):1404-12. doi: 10.1097/ICO.0000000000000598.
To improve keratoconus (KC) screening with new in vivo biomechanical Scheimpflug analyses.
After adjusting for intraocular pressure and corneal thickness, predefined static and new dynamic Scheimpflug curve analyses [Pentacam HR and Corvis ST (CST); Oculus] of 87 normal eyes, 27 subclinical KC eyes, 42 suspected KC, and 65 manifest KC eyes were reviewed retrospectively. A t test (for a normal distribution), Wilcoxon matched-pairs test (if not normally distributed), and receiver operating characteristics were used to test for statistically significant differences between these groups. In addition, new dynamic curve analyses were performed to analyze corneal dynamics throughout the entire response to the CST air puff impulse.
Comparing normal and KC-suspect eyes, the parameters A1 length, A2 length, radius of the inward-bended cornea, and deflection length at the highest concavity revealed statistically significant differences. In addition, the newly calculated "applanation length level" and "deflection length level" demonstrated consistently increasing differences with increasing statistical significance between normal eyes and those with advancing KC stages. However, when comparing normal and subclinical KC eyes, none of the analyzed parameters demonstrated statistically significant differences.
In vivo biomechanical analyses (CST) at their current state only marginally improve KC screening protocols. Newly generated parameters such as the applanation length level and deflection length level might further improve early KC screening.
通过新的活体生物力学Scheimpflug分析改进圆锥角膜（KC）筛查。
在对眼压和角膜厚度进行校正后，回顾性分析了87只正常眼、27只亚临床KC眼、42只疑似KC眼和65只显性KC眼的预定义静态和新动态Scheimpflug曲线分析[Pentacam HR和Corvis ST（CST）；Oculus]。采用t检验（用于正态分布）、Wilcoxon配对检验（若非正态分布）和受试者工作特征曲线来检验这些组之间的统计学显著差异。此外，进行了新的动态曲线分析，以分析角膜在对CST气流脉冲的整个反应过程中的动力学。
比较正常眼和疑似KC眼，参数A1长度、A2长度、向内弯曲角膜的半径以及最高凹度处的偏转长度显示出统计学显著差异。此外，新计算的“压平长度水平”和“偏转长度水平”显示，随着KC病情进展，正常眼与KC眼之间的差异持续增加，且统计学显著性不断提高。然而，比较正常眼和亚临床KC眼时，所分析的参数均未显示出统计学显著差异。
目前状态下的活体生物力学分析（CST）仅能在一定程度上改进KC筛查方案。新生成的参数如压平长度水平和偏转长度水平可能会进一步改善早期KC筛查。
