Interferometric analysis of diffractive multifocal intraocular lenses.

PURPOSE: To characterize the surface metrology of 4 multifocal intraocular lenses (IOLs) and simulate their behavior across pupil sizes. SETTING: Physiological Optics & Imaging Laboratory, Daegu, South Korea. DESIGN: Laboratory investigation. METHODS: Four +20.0-diopter multifocal IOLs-Envy, PanOptix, Odyssey, and Synergy-were evaluated using a Mach-Zehnder interferometer (NIMO TEMPO) following ISO 11979-2 standards. Optical path difference maps generated wavefront profiles, diffractive step profiles, point spread functions, and modulation transfer functions (MTFs). Through-focus MTFs were obtained at 50 line pairs per millimeter under of 2.0 mm, 3.0 mm, and 4.5 mm pupil diameters. RESULTS: Envy exhibited gradually decreasing diffractive step heights peripherally, favoring distance vision under mesopic conditions. PanOptix maintained uniform step heights, whereas Odyssey and Synergy exhibited larger diffractive steps with significant primary and secondary spherical aberrations, producing extended depth-of-field. Odyssey exhibited a distance-dominant energy distribution, while Synergy displayed a more balanced intermediate and near dispersal. Through-focus MTFs revealed stable trifocal peaks for Envy, a near-shifted tendency for PanOptix under small pupils, and far-dominant patterns for Odyssey and Synergy converging under larger pupils. CONCLUSIONS: Interferometric optical metrology revealed distinct through-focus optical profiles among contemporary diffractive multifocal IOLs, reflecting design-dependent differences in focal energy distribution across pupil sizes.