Improved IOL Power CalculationWith Femtosecond Laser Enhanced Refractive Outcome Prediction

Abstract

Purpose: The purpose of this study was to introduce and evaluate the femtosecond laser enhanced refractive outcome (FLERO) prediction method, an intraocular lens (IOL) calculator that augments Barrett Universal II (BUII) by integrating novel anterior segment optical coherence tomography (OCT) biometric predictors obtained during femtosecond laser-assisted cataract surgery (FLACS).

Methods: Two thousand, three hundred sixty-three (2363) eyes of 1720 patients (mean age = 71.33 years, 60.26% women) undergoing FLACS were analyzed. FLERO was developed by selecting the most predictive subset of OCT-derived biometry features using a “genetic algorithm” and combining them with BUII predictions in a linear model. Internal validation was performed through cross-validation, and prediction errors (PEs) were compared with BUII and Kane errors.

Results: Compared to BUII, FLERO increased the proportion of eyes achieving postoperative refraction within ±0.25 diopter (D), ±0.50 D, and ±1.00 D of target from 0.470 to 0.507, 0.781 to 0.824, and 0.962 to 0.970, respectively. Mean absolute error decreased from 0.345 D for BUII and 0.338 D for Kane to 0.315 D for FLERO. FLERO outperformed BUII and Kane across (short, medium, and long) eyes, where proportions of eyes achieving refraction within ±0.50 D were 0.696, 0.831, and 0.782 for FLERO, 0.468, 0.796, and 0.718 for BUII, and 0.595, 0.798, and 0.718 for Kane. Wilcoxon Signed-Rank testing indicated significant reductions in absolute PEs for FLERO versus BUII and Kane (P < 0.0001). PE regression revealed FLERO made significantly smaller errors.

Conclusions: FLERO enhances BUII by incorporating novel OCT-derived FLACS biometric parameters across short, medium, and long eyes.