Comparison of the Accuracies of Intraocular Lens Power Formulae by the Type of Implanted Lens

ABSTRACT

Purpose@#We compared the accuracies of formulae used to calculate intraocular lens (IOL) powers when predicting postoperative refraction, by the type of lens. @*Methods@#We retrospectively reviewed the medical records of 445 eyes (332 patients) that had undergone phacoemulsification and posterior chamber lens implantation between January 2017 and December 2019. Axial length was measured via optical low-coherence reflectometry (Lenstar LS900; Haag-Streit, Bern, Switzerland). The IOLs implanted were all one-piece acrylic IOLs, thus, the ALCON SN60WF (215 eyes), the TECNIS ZCB00 (139 eyes), and the MBI SAL302AC (91 eyes). The mean absolute errors (MAEs) and mean numerical errors (MNEs) were calculated using the SRK-2, SRK/T, Hoffer Q, Holladay, Olsen, and Barrett formulae 1-2 weeks after surgery. @*Results@#For the ALCON SN60WF, the Hagis formula yielded the lowest power and thus tended to be myopic, but we found no significant difference in the MAE. For the TECNIS ZCB00, the Olsen formula yielded the lowest power and thus tended to be myopic, and the Barrett formula yielded the lowest MAE. For the MBI SAL302AC, all MAEs and MNEs were similar. @*Conclusions@#Depending on the IOL type, the IOL power calculation formulae differed in terms of predicting postoperative refraction.