Posters

Effect of decentration on the optical quality of multifocal intraocular lenses

Poster Details

First Author: C.Ortiz SPAIN

Co Author(s):    L. Belda-Salmerón   J. Esteve-Taboada   T. Ferrer-Blasco   R. Montés-Micó     

Abstract Details

Purpose:

To compare the in vitro optical performance of a diffractive bifocal intraocular lens (IOL) and a new trifocal IOL at different degrees of decentration using an optical bench.

Setting:

University of Granada and University of Valencia, Spain.

Methods:

The Acri.LISA 366D IOLs (+3.75 D add) and the AT LISA tri 839MP with three main foci (Carl Zeiss Meditec) were evaluated. The optical quality of the IOLs was assessed in vitro using a PMTF optical bench (Lambda-X Co) with an aberration-free model cornea. This equipment allows to measure the modulation transfer function (MTF) by imaging an edge and then, processing the image. The two diffractive multifocal IOLs were evaluated both centered and decentered (0.2 and 0.4 mm). At each position, the MTF for each focus and the through-focus MTF at least at 10 different focal points (steps of 0.5 D) were measured for 3 and 4.5 mm aperture diameters.

Results:

The through-focus MTF curves showed two and three peaks for the bifocal and trifocal IOLs, respectively, with 3 and 4.5 mm aperture diameters and for both centered and decentered positions. The optical quality outcomes of the bifocal IOL were better than those obtained with the trifocal IOL at far and near distances, even when the IOL was decentered. However, for the intermediate vision, the trifocal IOL provided the best MTF values. In addition, we found that optical quality was deteriorated with decentration, showing a higher impact for larger aperture diameters.

Conclusions:

The creation of an intermediate focus provides better optical quality at intermediate vision, however, a decrease in optical quality could be obtained at far and near distances compared to the bifocal IOL. The deterioration of optical quality caused by decentration was higher for larger pupil sizes. Therefore, decentration could affect to the patient`s visual performance, particularly for activities which require low-illumination levels. FINANCIAL INTEREST: NONE