No-History IOL Power Calculation After Myopic Laser Vision Correction: A Multicenter Retrospective Database Study of 14 Formulas With and Without Posterior Corneal Curvature.

Abstract

To investigate intraocular lens (IOL) power formulas in eyes with prior myopic laser vision correction (M-LVC). Retrospective evaluation of IOL power calculation accuracy. The study included 3,738 eyes from 3,738 patients undergoing routine cataract surgery by 145 surgeons across multiple U.S. centers between October 2, 2017, and August 20, 2025. Veracity database (Carl Zeiss) was used; M-LVC eyes were identified from surgeon-reported history without independent verification. Biometry was obtained with the IOLMaster 700, and subjective refraction was measured 21-90 days postoperatively. Refractive prediction errors were calculated for 14 formulas: early-generation formulas (Haigis-L and Shammas-PL), modern formulas with and without posterior corneal curvature (PCC) input (Barrett True K, Cooke K6 [K6], EVO 2.0, Hoffer QST, PEARL-DGS), Shammas-Cooke (without PCC), and Haigis-TK (with PCC). Main outcome measures were mean absolute error (MAE) and proportions of eyes within ±0.50 D and ±1.00 D of target refraction. Formulas were ranked by MAE, and pairwise comparisons were conducted using heteroscedastic testing with Holm's correction. Modern formulas outperformed early-generation formulas, while PCC-adjusted formulas demonstrated lower MAEs than their non-PCC counterparts (p <0.0001). Among non-PCC formulas, K6 and EVO 2.0 (both MAE 0.40 D) ranked best, while Shammas-Cooke (0.42 D) outperformed Barrett True K (0.45 D), Haigis-L (0.48 D), Hoffer QST (0.49 D), and Shammas-PL (0.57 D). Among PCC formulas, K6 (0.37 D), PEARL-DGS (0.38 D), EVO 2.0 (0.38 D), and Barrett True K (0.38 D) ranked best. Modern formulas showed the greatest benefit in extreme eyes. In steep corneas (43 D to <45 D and ≥45 D), K6 increased the proportion within ±0.50 D by 8.4 and 10.4%, respectively, compared with Barrett True K. In short eyes (AL <23.5 mm), K6 achieved >13% more eyes within ±0.50 D and reduced MAE by 0.1 D. In eyes with satisfactory postoperative visual acuity, modern formulas outperform early-generation formulas, and PCC-based versions are preferable. With AL <23.5 or K >43 D (22% of these eyes), online modern formulas-particularly K6 and EVO 2.0-provided the greatest accuracy gain vs. Barrett True K. In typical post-M-LVC eyes, such gains are clinically negligible. When full biometry is unavailable, Shammas-Cooke is a reasonable alternative.