Sideroudi Haris, Labiris Georgios, Ditzel Fienke, Tsaragli Efi, Georgatzoglou Kimonas, Siganos Haralampos, Kozobolis Vassilios
Eye Institute of Thrace, Democritus University of Thrace, Alexandroupolis, Greece.
Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece.
Int Ophthalmol. 2018 Aug;38(4):1433-1440. doi: 10.1007/s10792-017-0602-7. Epub 2017 Jun 15.
The aim was to assess the repeatability of Fourier transfom analysis of videokeratographic data using Pentacam in normal (CG), keratoconic (KC) and post-CXL (CXL) corneas.
This was a prospective, clinic-based, observational study. One randomly selected eye from all study participants was included in the analysis: 62 normal eyes (CG group), 33 keratoconus eyes (KC group), while 34 eyes, which had already received CXL treatment, formed the CXL group. Fourier analysis of keratometric data were obtained using Pentacam, by two different operators within each of two sessions. Precision, repeatability and Intraclass Correlation Coefficient (ICC), were calculated for evaluating intrassesion and intersession repeatability for the following parameters: Spherical Component (SphRmin, SphEcc), Maximum Decentration (Max Dec), Regular Astigmatism, and Irregularitiy (Irr). Bland-Altman analysis was used for assessing interobserver repeatability.
All parameters were presented to be repeatable, reliable and reproductible in all groups. Best intrasession and intersession repeatability and reliability were detected for parameters SphRmin, SphEcc and Max Dec parameters for both operators using ICC (intrasession: ICC > 98%, intersession: ICC > 94.7%) and within subject standard deviation. Best precision and lowest range of agreement was found for the SphRmin parameter (CG: 0.05, KC: 0.16, and CXL: 0.2) in all groups, while the lowest repeatability, reliability and reproducibility was detected for the Irr parameter.
The Pentacam system provides accurate measurements of Fourier tranform keratometric data. A single Pentacam scan will be sufficient for most clinical applications.
本研究旨在评估使用Pentacam对正常角膜（CG）、圆锥角膜（KC）和角膜交联术后（CXL）角膜的视频角膜地形图数据进行傅里叶变换分析的可重复性。
这是一项基于临床的前瞻性观察性研究。分析纳入了所有研究参与者中随机选择的一只眼睛：62只正常眼睛（CG组），33只圆锥角膜眼睛（KC组），以及34只已接受角膜交联治疗的眼睛组成CXL组。使用Pentacam由两名不同操作人员在两个时间段内分别获取角膜曲率数据的傅里叶分析结果。计算精度、可重复性和组内相关系数（ICC），以评估以下参数在时间段内和时间段间的可重复性：球镜成分（SphRmin、SphEcc）、最大偏心度（Max Dec）、规则散光和不规则度（Irr）。采用Bland-Altman分析评估观察者间的可重复性。
所有组的所有参数均表现出可重复性、可靠性和可再现性。使用ICC（时间段内：ICC>98%，时间段间：ICC>94.7%）和个体内标准差，发现两名操作人员对于SphRmin、SphEcc和Max Dec参数在时间段内和时间段间具有最佳的可重复性和可靠性。所有组中SphRmin参数的精度最佳且一致性范围最低（CG组：0.05，KC组：0.16，CXL组：0.2），而Irr参数的可重复性、可靠性和可再现性最低。
Pentacam系统能够准确测量傅里叶变换角膜曲率数据。单次Pentacam扫描对于大多数临床应用就足够了。
