Posters

Comparison of a trifocal toric and a bifocal toric intraocular lens under simulated conditions of decentration and tilt

Poster Details

First Author: E.Papadatou SPAIN

Co Author(s):    G. Zoulinakis   A. Moulakaki   D. Madrid-Costa   T. Ferrer-Blasco           

Abstract Details

Purpose:

To compare in vitro the effect of decentration and tilt in the optical quality of a trifocal toric and a bifocal toric intraocular lens.

Setting:

University of Valencia, Spain

Methods:

The optical quality of the AT LISA tri toric 939MP (Zeiss) IOL with two addition powers (1.66 D and 3.33 D) and the AT LISA toric 909MP (Zeiss) IOL with one addition power (3.75 D) were evaluated under simulated conditions of decentration (0.2 mm and 0.4 mm) and tilt (5 degrees). All the measurements were performed for two apertures sizes (3 mm and 4.5 mm) and compared to the well-centered positions by means of Strehl Ratio. The PMTF optical bench (Lambda-X) was used to assess the optical quality of the IOLs using an aberration–free model cornea.

Results:

The results showed better optical performance for the bifocal at 3 mm than at 4.5 mm aperture especially for the far focus, in every simulated condition. For the trifocal better optical performance was observed for the 4.5 mm aperture in every foci. Decentration and tilt decreased the optical quality of both lenses. For the 0.4 mm decentered position the bifocal did not give outcomes. For the tilted position both lenses yielded similar results.

Conclusions:

Decentration and tilt led to a gradual deterioration in optical quality of both IOLs with the effect being more pronounced for the bifocal lens. The trifocal, although yielded poorer results at the 3 mm aperture for the far focus, proved to be less affected by the pupil size. The fact that the bifocal lens did not reach the 0.4 mm of decentration relies on the nominal power of the lens which was almost two times higher than the bifocal. In both lenses, the effect of tilt led to higher optical quality decrement than decentration.

Financial Disclosure:

NONE