Wang Chunxiao, Xia Xueying, Tian Bishan, Zhou Shiyou
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060, China.
Guangdong Women and Children Hospital, Guangzhou, Guangdong 510000, China.
J Ophthalmol. 2015;2015:402925. doi: 10.1155/2015/402925. Epub 2015 Jun 25.
Objective. To compare fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT (TD-OCT) in the determination of thinnest corneal thickness (TCT). Methods. This study included 55 keratoconus patients and 50 healthy volunteers. The RTVue-OCT (FD-OCT) and Visante-OCT (TD-OCT) were used for the measurement of the TCT. Three consecutive scans were performed. The comparison and agreement between the two modalities were analyzed by paired t-test, the Pearson correlation, intraclass correlation coefficient (ICC), and Bland-Altman plots. intraobserver repeatability was analyzed by the intraobserver within-subject standard deviation (S (w)), coefficient of variation (CV(w)), and ICC. Results. The TCT value of normal corneas was higher by RTVue-OCT (530.4 ± 19.7 μm) than Visante-OCT (521.5 ± 18.3 μm) (p < 0.001). For keratoconus eyes, the TCT was 425.0 ± 58.2 μm and 424.4 ± 55.7 μm (difference being 0.6 ± 10.2 μm, p = 0.604). Strong correlation (r = 0.938∼0.985) (ICC = 0.915-0.984) was observed between the two OCTs, and each OCT exhibited excellent repeatability in determining the TCT in all subjects (ICC = 0.984-0.994). Conclusions. The values of TCT obtained from RTVue-OCT and Visante-OCT were highly correlated; however, the two values were different. Both OCT instruments exhibited good intraobserver reliability. The existence of systematic differences suggested that the two instruments cannot be used interchangeably.
目的。比较傅里叶域光学相干断层扫描（FD-OCT）和时域光学相干断层扫描（TD-OCT）在测定最薄角膜厚度（TCT）方面的差异。方法。本研究纳入了55例圆锥角膜患者和50名健康志愿者。使用RTVue-OCT（FD-OCT）和Visante-OCT（TD-OCT）测量TCT。进行连续三次扫描。通过配对t检验、Pearson相关性分析、组内相关系数（ICC）和Bland-Altman图分析两种方法之间的比较和一致性。观察者内重复性通过观察者内受试者标准差（S（w））、变异系数（CV（w））和ICC进行分析。结果。正常角膜的TCT值通过RTVue-OCT（530.4±19.7μm）测量高于Visante-OCT（521.5±18.3μm）（p<0.001）。对于圆锥角膜眼，TCT分别为425.0±58.2μm和424.4±55.7μm（差异为0.6±10.2μm，p = 0.604）。两种OCT之间观察到强相关性（r = 0.938～0.985）（ICC = 0.915 - 0.984），并且每种OCT在所有受试者中测定TCT时均表现出极好的重复性（ICC = 0.984 - 0.994）。结论。从RTVue-OCT和Visante-OCT获得的TCT值高度相关；然而，这两个值不同。两种OCT仪器均表现出良好的观察者内可靠性。系统差异的存在表明这两种仪器不能互换使用。
