[Comparison of keratometric measurements obtained by the Verion image guided system with the IOLMaster and the Pentacam before cataract extraction surgery].

Objective: To compare the keratometric measurements of the Verion image guided system with the partial coherence interferometry (IOLMaster700) and the scheimpflug corneal topography (Pentacam). Methods: In this cross-sectional study, 146 eyes of 88 patients [mean age, (69±10) years; 62 eyes of male patients and 84 eyes of female patients] with cataract were examined before cataract extraction and IOL implantation surgery in the Tenth People's Hospital Affiliated to Tongji University from January 2016 to March 2017. Corneal curvature values acquired by the Verion optical imaging system were compared with the IOLMaster700 and the Pentacam. Keratometric data, magnitude of astigmatism, and steep astigmatic axis measurements from all three instruments were also compared. According to the steep axis of astigmatism, the eyes were divided into groups of with the rule (WTR), against the rule (ATR), and oblique astigmatism. The parameter differences between the Verion and the other devices in the three groups were analyzed. The data were evaluated using repeated measures analysis of variance and Bland-Altman plots. Results: The values of steep keratometry (Ks) of the Verion, IOLMaster700, and Pentacam were (44.60±1.32), (44.73±1.37), (44.43±1.35) D, respectively. The values of flat keratometry (Kf) of the Verion, IOLMaster700, and Pentacam were (43.51±1.41), (43.51±1.52), (43.40±1.45) D, respectively. The values of mean keratometry (Km) of the Verion, IOLMaster700, and Pentacam were (44.60±1.32), (44.12±1.35), (43.92±1.34) D, respectively. The values of astigmatism magnitude were (1.09±0.87), (1.24±1.02), (1.04±0.80) D, respectively. The F values were 1.81, 0.31, 0.93 and 2.22 in relation to Ks, Kf, Km and corneal astigmatism magnitude among the three instruments, respectively (all P>0.05). The 95% confidence intervals of Kf, Ks and astigmatism magnitude between the Verion and the other two devices were -1.10 to 0.80 D, -0.55 to 0.88 D; -1.10 D to 1.10 D, -0.80 to 1.04 D; -1.21 to 0.90 D, -0.92 to 1.02 D. The outcomes were considered acceptable. There were no statistically differences in steep astigmatic axis measurements between the Verion and the other two instruments among the WTR (62 eyes), ATR (45 eyes) and oblique (15 eyes) groups (F=0.63, 0.37; P=0.54, 0.72, respectively). Conclusions: The Verion image guided system is a reliable system for the measurement of keratometry values and astigmatism. The keratometric power, magnitude and steep axis of astigmatism have no significant difference, and there is a good agreement among the Verion, IOL Master 700, and Pentacam. (Chin J Ophthalmol, 2020, 56: 47-52).目的： 比较Verion数字导航系统与IOLMaster700、Pentacam在白内障摘除手术联合人工晶状体（IOL）植入术前测量角膜散光的差异及一致性。 方法： 横断面研究。收集2016年1月至2017年3月于同济大学附属第十人民医院眼科拟行Verion数字导航系统辅助下的超声乳化白内障吸除联合IOL植入术的88例（146只眼）白内障患者[年龄（69±10）岁；男性62只眼，女性84只眼]，术前分别用上述3种仪器测量陡峭轴角膜曲率（Ks）、平坦轴角膜曲率（Kf）、平均角膜曲率（Km）、角膜散光度数、陡峭轴散光轴位。将3种方法测量的陡峭轴散光轴位按照散光轴位方向分为顺规散光组、逆规散光组和斜向散光组。3种仪器间测量结果及组间散光轴位差值的比较采用重复测量的方差分析，一致性检验采用Bland-Altman分析。 结果： Verion、IOLMaster 700和Pentacam的Ks检测值分别为（44.60±1.32）、（44.73±1.37）、（44.43±1.35）D，Kf检测值分别为（43.51±1.41）、（43.51±1.52）、（43.40±1.45）D，Km检测值分别为（44.06±1.30）、（44.12±1.35）、（43.92±1.34）D，散光度数分别为（1.09±0.87）、（1.24±1.02）、（1.04±0.80）D，3种方法间检测值差异均无统计学意义（F=1.81，0.31，0.93，2.22；均P>0.05）。Bland-Altman分析显示Verion与IOLMaster700、Verion与Pentacam测量Ks一致性比较的95%可信区间分别为-1.10~0.80 D、-0.55~0.88D；Kf一致性比较的95%可信区间分别为-1.10~1.10 D、-0.80~1.04 D；角膜散光度一致性比较的95%可信区间分别为-1.21~0.90 D、-0.92~1.02 D，3种设备计算Ks、Kf、角膜散光幅度一致性均在临床可接受范围。顺规散光组（62只眼）、逆规散光组（45只眼）和斜向散光组（15只眼）组间陡峭轴散光轴位的Verion与IOLMaster700、Verion与Pentacam测量差值差异均无统计学意义（F=0.63，0.37；均P>0.05）。 结论： Verion与IOLMaster700、Pentacam在白内障摘除联合IOL植入术前测量角膜曲率、散光度数和轴位方面无明显差别，3种测量方法的一致性较好。（中华眼科杂志，2020，56：47-52）.