Comparison of Legacy and New No-History IOL Power Calculation Formulas in Postmyopic Laser Vision Correction Eyes

Highlights•IOL calculations in postmyopic laser vision M-LVC (M-LVC) are difficult compared to non-LVC eyes.•Recently, new no-history post-M-LVC formulas and using new methods for obtaining corneal power s have been suggested for post-M-LVC eyes.•New M-LVC formulas using posterior keratometry (PK) values obtained from the IOLMaster700 are superior to counterpart versions that do not include PK values.•New M-LVC formulas that do not use PK are superior to legacy M-LVC formulas.AbstractPurposeTo compare the refractive accuracy of legacy and new no-history formulas in eyes with previous myopic laser vision correction (M-LVC).DesignRetrospective cohort study.MethodsSetting: Two academic centers Study Population: 576 eyes (400 patients) with previous M-LVC that underwent cataract surgery between 2019-2023. A SS-OCT biometer was used to obtain biometric measurements, including standard (K), posterior (PK), and total keratometry values (TK).Observation Procedures: Refractive prediction errors were calculated for 11 no-history formulas: two legacy M-LVC formulas, four new M-LVC formulas using K values only, and five new M-LVC formulas using K with PK or TK. Main Outcome Measures: Heteroscedastic testing was used to evaluate relative formula performance, and formulas were ranked by root mean square error (RMSE).ResultsNew M-LVC formulas performed better than legacy M-LVC formulas. New M-LVC formulas with PK/TK values performed better than versions without PK/TK values. Among new M-LVC formulas with PK/TK values, EVO 2.0-PK was superior to Hoffer QST-PK (P < 0.005). Among new M-LVC formulas using K only, Pearl DGS-K and EVO 2.0-K were both superior to Hoffer QST-K and Barrett True K NH-K formulas (all P < 0.005).ConclusionsSurgeons should favor using new no-history post M-LVC formulas over legacy post M-LVC formulas whenever possible. The top-performing M-LVC formulas (EVO 2.0-PK, Pearl DGS-PK, and Barrett True K-TK) utilized posterior corneal power values. Among formulas utilizing K alone, the EVO 2.0-K and Pearl DGS-K performed best.