Trifocality achieved through Polypseudophakia: Optical quality and light loss compared with a single trifocal intraocular lens

Abstract

PURPOSE: To compare the optical performance of a two-intraocular lens (IOL) system with that of a single capsular bag trifocal IOL. METHODS: The two-IOL configuration of a monofocal RayOne Aspheric (Rayner Intraocular Lenses, Ltd) and a Sulcoflex Trifocal (Rayner Intraocular Lenses, Ltd) lens was compared in vitro with a single-lens option (RayOne Trifocal; Rayner Intraocular Lenses, Ltd). Two samples of each IOL model were studied with an optical metrology device. The optical quality was assessed using the area under the modulation transfer function (MTF). The impact of the supplementary lens misalignment on the MTF was tested. The light loss was also measured using a power meter. RESULTS: The two-IOL system produced three well-defined focal peaks comparable to those of the single lens. The MTF area of the single- and two-IOL configuration was, respectively, 22.5 and 20.7 at far, 16.4 and 15.4 at intermediate, and 14.9 for each configuration at near. A moderate decentration (up to 0.6 mm) had a minimal effect at intermediate and near on the supplementary lens MTF and no impact at far. A 5° tilt did not alter the MTF. The supplementary lens caused a 1.3% decrease in the optical power. CONCLUSIONS: The optical quality of the two-IOL system matched that of the single trifocal lens. A low-power supplementary IOL demonstrated high tolerance to misalignment and minimal light attenuation. The reversibility of the two-IOL approach may prove advantageous clinically.