Ferreira Tiago B, Ribeiro Filomena J
Department of Ophthalmology, Hospital da Luz, Lisbon, Portugal.
Clin Ophthalmol. 2017 Dec 20;12:29-34. doi: 10.2147/OPTH.S146730. eCollection 2018.
To assess the comparability and repeatability of keratometric and astigmatism values measured by four techniques: Orbscan IIz (Bausch and Lomb), Lenstar LS 900 (Haag-Streit), Cassini (i-Optics), and Total Cassini (anterior + posterior surface), in healthy volunteers.
Fifteen healthy volunteers (30 eyes) were assessed by the four techniques. In each eye, three consecutive measures were performed by the same operator. Keratometric and astigmatism values were recorded. The intraclass correlation coefficient (ICC) was used to assess comparability and repeatability. Agreement between measurement techniques was evaluated with Bland-Altman plots.
Comparability was high between all measurement techniques for minimum keratometry (K1), maximum keratometry (K2), astigmatism magnitude, and astigmatism axis, with ICC >0.900, except for astigmatism magnitude measured by Cassini compared to Lenstar (ICC =0.798) and Orbscan compared to Lenstar (ICC =0.810). However, there were some differences in the median values of K1 and K2 between measurement techniques, and the Bland-Altman plots showed a wide data spread for all variables, except for astigmatism magnitude measured by Cassini and Total Cassini. For J0 and J45, comparability was only high for J0 between Cassini and Orbscan. Repeatability was also high for all measurement techniques except for K2 (ICC =0.814) and J45 (ICC =0.621) measured by Cassini.
All measurement techniques showed high comparability regarding K1, K2, and astigmatism axis. Although posterior corneal surface is known to influence these measurements, comparability was high between Cassini and Total Cassini regarding astigmatism magnitude and axis. However, the wide data spread suggests that none of these devices should be used interchangeably.
评估在健康志愿者中，通过四种技术测量的角膜曲率和散光值的可比性和可重复性，这四种技术分别为：Orbscan IIz（博士伦公司）、Lenstar LS 900（ Haag-Streit公司）、Cassini（i-Optics公司）以及Total Cassini（前后表面测量）。
15名健康志愿者（30只眼）接受了这四种技术的评估。在每只眼中，由同一名操作人员连续进行三次测量。记录角膜曲率和散光值。使用组内相关系数（ICC）评估可比性和可重复性。通过Bland-Altman图评估测量技术之间的一致性。
对于最小角膜曲率（K1）、最大角膜曲率（K2）、散光度数和散光轴，所有测量技术之间的可比性都很高，ICC>0.900，但Cassini测量的散光度数与Lenstar测量的相比（ICC = 0.798）以及Orbscan测量的与Lenstar测量的相比（ICC = 0.810）除外。然而，测量技术之间K1和K2的中位数存在一些差异，并且Bland-Altman图显示所有变量的数据分布范围都很广，但Cassini和Total Cassini测量的散光度数除外。对于J0和J45，只有Cassini和Orbscan之间J0的可比性较高。除了Cassini测量的K2（ICC = 0.814）和J45（ICC = 0.621）外，所有测量技术的可重复性也很高。
所有测量技术在K1、K2和散光轴方面都显示出很高的可比性。尽管已知角膜后表面会影响这些测量，但Cassini和Total Cassini在散光度数和轴方面的可比性很高。然而，广泛的数据分布表明这些设备都不应互换使用。
