Comparison of current intraocular lens power calculation formula in cataract patients

BACKGROUND: In patients who undergoing cataract surgery the new intraocular lens (IOL) calculation formulas such as Kane, Barrett II Universal (BUII), Ladas Super formula and EVO 2.0 formula, which are available online and free of charge, and the IOLs of Hoffer Q, SRK/T, Holladay I and Haigis formulas presented in the optical biometry device strength is to compare the accuracy. MATERIAL and METHODS: Three hundred and twelve patients who aged between 27-93 years were included in the study. Emetropization or the lowest myopic spherical equivalent was planned for the patients, and the appropriate numbered IOL was implanted using the formulas as a result of the measurements made with the preoperative optical low coherence reflectometry (Lenstar LS 900, Haag-Streit Koeniz, Switzerland) device. All measurements and surgeries were performed by the same experienced surgeon (AS) using the same devices. One month after surgery, refraction measurements of the patients were made with an autorefractometer, and their objective manifest refraction was determined, and their spherical equivalents were recorded. The eyes of the patients included in the study were divided into 3 groups according to their axial length as short, medium and long.Refractive results were determined as the spherical equivalent predicted refraction one month after surgery, and the spherical equivalent measured after surgery as the "manifest refraction" based on the lens formulas used. The mean of the difference between the predicted refraction and the manifest refraction was expressed as the "mean error". By taking the absolute value of the mean error, the "mean absolute error" (MAE) values were specified. Differences in absolute error between formulas were evaluated using the Friedman test. If a significant result was obtained, post hoc analysis was performed using the Wilcoxon signed-rank test for pairwise comparisons with Bonferroni correction as suggested by Aristodemou et al. P values less than 0.05 were considered significant. RESULTS: They are listed in order of MAE value for all axial lengths, from lowest to highest, as BUII, Kane, EVO 2.0, Ladas Super formula, Holladay I, Hoffer Q, SRK-T and Haigis formulas. For short axial lengths, the order of MAE values is from lowest to highest, BUII, Hoffer Q, Ladas Super formula, Kane, Haigis, Holladay I, EVO, and SRK-T. For mid-axial lengths, the order of MAE iv values was from lowest to highest, Kane, BUII, EVO 2.0, Ladas Super formula, Holladay I, Hoffer Q, SRK-T and Haigis. For long axial lengths, the order of OMH values was from lowest to highest, Kane, EVO 2.0, BUII, Ladas Super formula, SRK-T, Haigis, Holladay I and Hoffer Q. CONCLUSION: We found that BUII, Kane, EVO 2.0, Ladas Super formulas gave similar or statistically more successful results than Haigis, Holladay I, SRK-T, Hoffer Q formulas available in the Lenstar 900 device in our clinic. These formulas, which are easily accessible to all ophthalmologists around the world, free of charge, are very useful and effective.