Evaluation of biometric formulas in the calculation of intraocular lens according to axial length and type of the lens.

To compare the accuracy of the modern biometric formulas in cataract surgery according to axial length and lens type. It is a Cross-sectional design from 365 patients who underwent cataract surgery. The SRK/T, Hoffer Q, Haigis, and Holladay I formulas were extracted from the IOLMaster 500 biometer. Barret formulas and the Kane were obtained from the online calculator. Patients are classified according to axial length (AL) into three groups: AL ≤ 22 mm, 22 < AL < 25 mm, and AL ≥ 25 mm. In addition, implanted intraocular lenses are classified as Monofocal, extended focus, and Multifocal. There are no significant differences between the formulas. In short, the Kane formula was more accurate than the other biometric formulas. Kane and SRK/T were the most accurate in monofocal lenses, with the lowest residual refractive error. The Holladay I formula obtained the lowest mean absolute error with the highest number of eyes with minimum residual ± 0.5Dp in the multifocal lenses in the 22 < AL < 25 mm eyes. In the long AL eyes, SRK/T and Kane's obtained the lowest mean absolute error and the best percentage of eyes with ± 0.5Dp of residual refractive error. There are no significant differences between the formulas. However Kane's formula has shown high accuracy, especially in short and long eyes with monofocal lenses.