Accuracy of 8 Intraocular Lens Power Calculation Formulas in Eyes Undergoing Combined Phacovitrectomy

To evaluate prediction accuracy using the 4 new-generation formulas (Barrett Universal II (BUII), Emmetropia Verifying Optical 2.0 (EVO), Kane, and Ladas Super Formula (LSF)) and 4 traditional formulas (Haigis, Hoffer Q, Holladay 1, and SRK/T) in eyes undergoing combined phacovitrectomy.

This is a retrospective case series study. In total, 249 eyes of 249 patients undergoing combined phacovitrectomy were enrolled. A single-piece foldable monofocal IOL was implanted in each case. The patients were categorized into three subgroups according to axial length (AL) results.

Overall, the 4 new-generation formulas obtained lower mean absolute prediction error (MAE) and median absolute prediction error (MedAE) of 0.42 D to 0.45 D and 0.33 D to 0.36, and higher percentage of prediction error (PE) within ± 0.50 D (65.46%-67.87%). Regarding short eyes, the Haigis formula showed the lowest MedAE of 0.34 D and the highest percentage of PE within ± 0.50 D (68.42%) with no statistical difference, and satisfactory accuracy was achieved using all formulas (all p > 0.05). All formulas displayed better accuracy in medium eyes with lower MAE (0.41 D to 0.46 D), lower MedAE (0.33 D to 0.37 D), and higher percentage of PE within ± 0.50 D (62.42%-69.09%) except for Hoffer Q. Both EVO and BUII formulas revealed higher accuracy in long eyes with lower MAE (0.38 D to 0.41 D), lower MedAE ranging from 0.31 D to 0.33 D, and higher percentage of PE within ± 0.50 D of both 71.74%.

The 4 new-generation formulas showed higher accuracy overall, and higher accuracy was achieved using EVO and BUII formulas in long eyes. All formulas revealed satisfactory accuracy in short eyes. All formulas displayed better accuracy in medium eyes except for Hoffer Q.