可视化角膜生物力学分析仪测量青少年儿童中央角膜厚度的重复性及与扫频光源OCT的一致性分析

目的：评估可视化角膜生物力学分析仪（Corvis ST）测量青少年儿童中央角膜厚度（CCT）的重复性，并与前节CASIA SS-1000光学相干断层扫描仪（OCT）测量结果进行一致性分析。方法：系列病例研究。纳入2015年1-4月来温州医科大学附属眼视光医院进行视光检查的儿童44名，年龄8～14岁，除近视外无其他眼部疾病，先采用Corvis ST测量CCT，再采用SS-1000 OCT进行测量。仅分析右眼数据。组内相关系数（ICC）、Bland-Altman及重复测量方差分析用于评估Corvis ST测量CCT的重复性，配对t检验及Bland-Altman用于评估Corvis ST与SS-1000 OCT测量的一致性。结果：Corvis ST重复3次测量CCT的ICC为0.987，3次测量之间一致性界限分别是-15.6～16.2 μm、-15.7～13.4 μm、-16.0～13.1 μm。重复测量方差分析显示3次测量的差异无统计学意义。CorvisST与SS-1000 OCT测量CCT的均值分别为（553±28）μm和（540±28）μm，其中Corvis ST测得的CCT值比SS-1000 OCT厚13 μm，差异有统计学意义（t=-6.037，P<0.001）。2种仪器测量CCT的95%一致性界限为-15.2～41.6 μm。结论：Corvis ST测量儿童CCT具有很好的重复性，与SS-1000 OCT一致性较好，但是在临床工作中，还应考虑到其测量值的差异，不可直接替代。

Repeatability and Agreement in Measuring Adolescents and Children’s Corneal thickness with Corvis st and ss-1000 swept-source Optical Coherence tomography

Objective: To assess the repeatability of central corneal thickness (CCT) measurements in adolescents and children using the Corvis ST and to examine the agreement between Corvis ST and SS-1000 swept-source optical coherence tomography (SS-1000 OCT). Methods: In this case series study, 44 children who visited the Eye Hospital, Wenzhou Medical University, from January to April of 2015 were enrolled. The age rangewas between 8 to 14 years old. The subjects were myopic without any other disease. CCT measurements were obtained first with the Corvis ST and then with SS-1000 OCT. The data of the right eyes was analyzed. An intraclass correlation coefficient (ICC), Bland-Altman plots and repeated-measures analysis of variance (ANOVA) were used to assess the repeatability of the Corvis ST. Paired t-tests and Bland-Altman plots were used to compare the agreement between the two devices. Results: The mean ICC of the Corvis ST was 0.987. Bland-Altman plots showed agreement between any two of three measurements (95% limits of agreement was -15.6~16.2 μm, -15.7~13.4 μm, -16.0~13.1 μm, respectively). No statistical significance was found with repeated-measures ANOVA. The mean values of CCT acquired from Corvis ST and SS-1000 OCT were 553±29 μm and 540±28 μm. CCT measured by the Corvis ST was 13 μm thicker than that by SS-1000 OCT (t=-6.037, P<0.001). The 95% limits of agreement were -15.2~41.6 μm for these two devices. Conclusions: The Corvis ST shows excellent repeatability of CCT measurements in healthy children’s eyes. Though there is a good agreement between the two devices for CCT measurements,there are significant differences between them. The measurements acquired by Corvis ST should not be directly interchangeable with SS-1000 OCT measurements in clinical practice.