Clinical feasibility of the ESCRS IOL power calculator

Purpose: To assess the mean absolute error (MAE) of classic and modern intraocular lens (IOL) power calculation formulas to evaluate the feasibility of the ESCRS IOL Calculator. Setting: Department of Ophthalmology, Johannes Kepler University and Kepler University Clinic, Linz, Austria; Department of Ophthalmology, Medical University Graz, Graz, Austria. Methods: 337 eyes of 337 patients who underwent implantation of a monofocal IOL (PCB00) were included in this study. The classic IOL calculation formulas output by the biometry device (Barrett Universal II [BUII], Haigis, SRK/T, and HofferQ) and modern formulas implemented in the ESCRS calculator (BUII, Cooke K6, EVO, Hill-RBF, Hoffer QST, Kane, and Pearl-DGS) were evaluated. The MAE, the number of eyes within ±0.5, ±1.0, ±1.5, ±2.0 diopters (D) of the target refraction, the agreement between ESCRS formulas on the proposed IOL power, and the time factor for the input in the ESCRS calculator were evaluated. Results: The best performing ESCRS calculator formulas were Kane, EVO, and BUII with a MAE (SD) of 0.37 (0.30) D, 0.37 (0.32) D, and 0.38 (0.32) D. A lower, but not significant difference in MAE for ESCRS formulas compared with biometry formulas was observed. A significant difference was observed between Hoffer QST and all other formulas ( P < .01 for all). After excluding Hoffer QST, testing revealed a significant difference between ESCRS and biometry formulas ( P = .004). Conclusions: The ESCRS calculator allows efficient and up-to-date IOL calculations in routine clinical practice. The predictive accuracy of the ESCRS calculator is superior compared with older biometric formulas.