Purpose: This study aimed to determine the consistency of powers between IOL Master 700 and CASIA2.
Participants and methods: A total of 247 eyes of 247 patients with cataract were categorized into the with-the rule (WTR) astigmatism, against-the rule (ATR) astigmatism, and oblique astigmatism groups. We evaluated the correlation and consistency between IOL Master 700 and CASIA2 in each group. Statistical analysis was performed using correlation analysis and Bland-Altman analysis methods using variables with refractive power (K value) and astigmatic power (cyl value) of the anterior, posterior, and anterior-posterior corneal surfaces.
Results: Anterior corneal K and Cy1 values exhibited positive intermodel correlation (r=0.46-0.99, p<0.05), and 95% limits of agreement (95% LoA) values were greater than 0.25 D in all groups. The Cy1 value showed a proportional bias (r=0.25, -0.37, p<0.05) in the WTR astigmatism and oblique astigmatism groups. The posterior corneal K value exhibited positive intermodal correlation (r=0.99, p<0.05), but a fixed bias (p<0.05) was present in all groups. Additionally, a proportional bias(r=-0.26, p<0.05)was found in the ATR astigmatism group. The posterior corneal Cy1 value was positively correlated between the models (r=0.72-0.82, p<0.05) in all groups, but a proportional bias (r=-0.30, p<0.05) was present in the ATR astigmatism group. The anterior-posterior corneal K and Cy1 values were positively correlated between the models (r=0.46-0.99, p<0.05), but 95% LoA values were greater than 0.25 D in all groups. The anterior-posterior corneal K value showed a fixed bias between the models (p<0.05) in all groups, and a proportional bias (r=0.32, p<0.05) was present in the ATR astigmatism group. The anterior-posterior corneal Cy1 value had a proportional bias (r=0.30, -0.35, p<0.05) in the WTR astigmatism and oblique astigmatism groups.
Conclusions: All variables in all astigmatism groups were correlated between the models, but they also included bias. Therefore, it is necessary to understand and compare the characteristics of both models and use them to determine the power of toric/astigmatic intraocular lenses.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 127: 1055-1062, 2023.