Correlation with a multifocal intraocular lens of in-vitro figures of merit with clinical visual acuity

Abstract

Purpose: To assesses the link between the in vitro optical properties of the PODFGF multifocal intraocular lens (IOL) and its visual acuity (VA) clinical performance. Setting: The study was conducted at TUDelft (NL), ULiege (BE), the Rothschild Institute (FR), and Beaver-Visitec International (BE). Design: The study analyzed 3 powers of the PODFGF IOL. The in vitro imaging quality was assessed using modulation transfer function (MTF) frequency sweep and through-focus MTF. Multiple figures of merit (FOMs), including MTF at 25-50-100 LP/mm, MTFa, and Strehl ratio, were extracted. Data acquisitions followed 2 ISO norms in green and white light conditions. The correlation with patients’ clinical VA was evaluated. Methods: The methodology had 2 parts: first, characterizing the in vitro properties of the IOL using FOMs, such as MTF, MTFa, and Strehl ratio, with multiple power samples (6 to 35 diopters). The second part analyzed the VA of 413 eyes implanted with FINEVISION-HP (PODFGF). Over 2 years, subjective refraction, uncorrected distance VA, corrected distance VA, uncorrected intermediate VA, distance-corrected intermediate VA, uncorrected near VA, distance-corrected near VA, defocus curve, photopic and mesopic contrast sensitivity, and rotational stability were analyzed. Results: The correlation between in vitro MTFa evaluated from the experimental data on IOLs and the clinical VA performed on implanted patients leads to an accurate prediction of vision capabilities after surgery. Conclusions: This study clinically demonstrates on a large patient cohort that MTFa complements single-frequency MTFs and establishes a mathematical link between MTF at 50 LP/mm, MTFa, and VA. In addition, it connects the 2 ISO model-eye standards and highlights the link between green and white light measurements in accurately predicting VA.