Posters

Longitudinal chromatic aberration of monofocal and multifocal intraocular lenses: an in vitro study

Poster Details

First Author: G.Labuz GERMANY

Co Author(s):    H. Son   R. Khoramnia   G. Auffarth              

Abstract Details

Purpose:

Longitudinal chromatic aberration (LCA) is caused by dispersion of polychromatic light, which results in dividing the light into its spectral components that are focused at different locations on the optical axis. This optical phenomenon has a deleterious effect on the polychromatic-image quality of an optical system. LCA has been reported in pseudophakic eyes, but recent designs of multifocal IOLs have been proposed to correct LCA of the eye after impanation. The goal of this study was to measure LCA of monofocal and multifocal IOLs, and to assess their polychromatic image quality.

Setting:

David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University of Heidelberg, Germany.

Methods:

We studied four multifocal IOLs, i.e. AT LARA 829MP and AT LISA 809M (Carl Zeiss), Restor SN6AD1 (Alcon), Mini Well Ready (SIFI), and three monofocal IOLs from these three manufacturers, i.e. CT Asphina, AcrySof IQ and Mini 4. An optical-bench device was used to evaluate LCA and optical quality metrics. The IOLs were measured in monochromatic light with interference filters (480, 546 and 644nm), and in polychromatic light. LCA was calculated as the power difference between a 480-nm and a 644-nm focus. The optical performance was assessed by means of modulation transfer function measurements and photographs of a resolution target.

Results:

LCA at a far/near focus of AT-Lara, AT-Lisa, Restor and Mini-Well were 0.78D/0.21D, 1.40D/0.26D, 1.91D/1.05D, and 1.27D/1.53D, respectively. A (far) LCA of the multifocal IOLs was compared with that of the monofocal IOLs. CT-Asphina showed an LCA of 1.41D, for ArySof-IQ it was 1.86D, and for Mini-4 it was 1.39D. At far, the polychromatic MTF was lower than that of the green light by 10%-20%. At near, a polychromatic and green-light performance of AT-Lara and AT-Lisa were comparable, but for Restor and Mini-Well the polychromatic MTF was reduced by 6% and 12%, respectively. Photographs showed characteristic ‘fringes’ of color.

Conclusions:

We demonstrated that all diffractive IOLs can effectively reduce LCA at the near focus, and in one case (AT-Lara) also at the far focus. A small (far) LCA difference between AT-Lisa and Restor, and their monofocal counterparts indicates that diffractive IOLs without chromatic-aberration correction have similar LCA as their monofocal platforms. We showed that LCA can affect the IOL performance in the polychromatic light, hence, LCA appears to be an important parameter that can influence vision in real-world (polychromatic) conditions.

Financial Disclosure:

receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, travel has been funded, fully or partially, by a competing company, travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented, research is funded, fully or partially, by a competing company, research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented, receives consulting fees, retainer, or contract payments from a competing company