Laboratory Evaluation of Halos and Through-Focus Performance of Three Different Multifocal Intraocular Lenses

To compare the halo features and through-focus performance of three different multifocal intraocular lenses (MIOLs) that provide distance, intermediate, and near vision in a clinical trial.

A trifocal diffractive MIOL (AT LISA tri 839MP; Carl Zeiss Meditec), a diffractive extended depth-of-focus MIOL (TECNIS Symfony ZXR00; Abbott Laboratories, Inc), and a rotational asymmetric refractive MIOL (SBL-3; Lenstec, Inc) were assessed in a modified International Organization for Standardization eye model. The modulation transfer function (MTF) at the IOLs' foci was obtained using aperture sizes of 3 and 4.5 mm. Through-focus MTF curves were compared among all MIOLs. Images of the slit pattern were used to assess halo formation and characteristics.

The AT LISA tri and Symfony IOLs showed symmetric halos. The halos of the AT LISA tri IOL were larger but weaker in distance and near foci, whereas the halos of the Symfony IOL were smaller and fainter in intermediate focus. The halos of the SBL-3 IOL were asymmetric and appeared as tangentially downward weaker halos. The optical performance of diffractive MIOLs gradually deteriorated as the aperture increased. The distance foci of the AT LISA tri and SBL-3 IOLs were of similar superior optical quality, the intermediate focus of the Symfony IOL showed the best optical quality, and the near focus of the SBL-3 IOL outperformed the near foci of the remaining IOLs.

The differences in the design of the MIOLs translate to differences in optical performance at their foci, through-focus expressions, and halo features, which can provide further information to surgeons when selecting what IOL to implant. [.