Abstract: Objective To compare the differences and agreement of IOLMaster 700 and Pentacam AXL in measuring Total keratometry and SimK in patients after FS-LASIK. Design Diagnostic technique evaluation. Participants A total of 89 patients (89 eyes) with myopia who underwent FS-LASIK surgery at the Refractive Surgery Center of Beijing Tongren Hospital. Methods The following parameters were recorded: SimK1, SimK2, Total K1 (TK1), and Total K2 (TK2) from IOLMaster 700; and SimK1, SimK2, TNP K1, TNP K2, TCRP K1, and TCRP K2 from Pentacam AXL. Bland-Altman plots were used to assess the consistency between the two devices. Paired t-tests were performed to compare the differences in the same parameters obtained by the two measurement instruments. Bland-Altman plots were used to assess the consistency between the two devices. Main Outcome Measures SimK1, SimK2, TK1, TK2, TNP K1, TNP K2, TCRP K1, TCRP K2.  Results The SimK1 and SimK2 measured by the IOLMaster 700 were (37.36±1.62) D and (38.12±1.67) D, respectively, showing no statistically significant difference compared to the measurements by Pentacam AXL, which were (37.33±1.68) D and (38.01±1.75) D (t=0.546, 1.552; P=0.586, 0.124). The TK1 measured by IOLMaster 700 was (36.60±1.81) D, which was greater than the TNP K1 (35.50±1.70) D (t=13.072, P<0.001) and TCRP K1 (35.82±1.85) D (t=9.202, P<0.001) measured by Pentacam AXL. Similarly, the TK2 measured by IOLMaster 700 was (37.25±1.87) D, greater than the TNP K2 (36.13±1.70) D (t=12.829, P<0.001) and TCRP K2 (36.41±1.79) D (t=10.205, P<0.001) measured by Pentacam AXL. The 95% limits of agreement (LoA) for SimK1, SimK2, TK1-TNP K1, TK2-TNP K2, TK1-TCRP K1, and TK2-TCRP K2 between the two devices were -1.3~1.3 D, -1.2~1.5 D, -0.6~2.8 D, -0.6~2.9 D, -0.9~2.5 D, and -0.8~2.5 D, respectively. The number of points within the 95% LoA were 84 (94.4%), 84 (94.4%), 84 (94.4%), 84 (94.4%), 82 (92.1%), and 85 (95.5%), respectively. Conclusion The measurements of SimK1 and SimK2 between the IOLMaster 700 and Pentacam AXL showed good consistency, and the results can be used interchangeably. Although the measurements of TK1, TK2, TNP K1, TNP K2, TCRP K1, and TCRP K2 also demonstrated relatively good consistency, there were certain differences in the values, and thus the results are not recommended for interchangeable use. (Ophthalmol CHN, 2025, 34: 152-156)

Key words: total keratometry, IOLMaster 700, Pentacam AXL