Agreement of white-to-white measurements with the IOLMaster 700, Atlas 9000, and Sirius systems

Background: Current advances in ocular surgery require the evaluation of differences in automated white-to-white (WTW) measurements between systems. We aim to analyze three different commonly used devices in clinical practice: the IOLMaster 700, the Atlas 9000, and the Sirius. Methods: Ninety right eyes of ninety healthy subjects were included. Measurements of WTW distances were taken with each device for all subjects in the same session and by the same observer. Statistical comparison was carried out by means of the rANOVA procedure and the Bonferroni post-hoc test. In addition, the Bland-Altman analysis was applied in order to perform pairwise comparisons. Results: Average WTW values obtained by the IOLMaster 700, the Atlas 9000, and the Sirius devices were 12.180.40-mm, 12.32 +/- 0.37-mm and 11.90 +/- 0.37-mm, respectively. There were statistically significant differences in all pairwise comparisons. Mean differences revealed that the Atlas 9000 provided the highest WTW values, followed by the IOLMaster 700 values and finally by the Sirius results, which had the lowest values. The limits of agreement obtained in all pairwise comparisons were wide, with a range between 0.64 and 0.75mm. Conclusions: According to our results, these three devices should not be used interchangeably for WTW diameter measurements during the clinical practice.