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

PURPOSE: To investigate intraocular lens (IOL) power formulas in eyes with prior myopic laser vision correction (M-LVC). DESIGN: Retrospective evaluation of IOL power calculation accuracy. SUBJECTS: 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. METHODS: 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: 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. RESULTS: 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. CONCLUSIONS: 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.