Halos after diffractive bifocal and trifocal intraocular lens implantation: objective and subjective evaluation

Session Details

Session Title: Presented Poster Session: Pseudophakic IOLs

Session Date/Time: Tuesday 08/09/2015 | 09:30-11:00

Paper Time: 10:10

Venue: Poster Village: Pod 3

First Author: : F.Alba-Bueno SPAIN

Co Author(s): :    N. Garzon   F. Poyales   F. Vega   M. Millan     

Abstract Details

Purpose:

To evaluate, with three different methods, the halos produced by bifocal and trifocal diffractive-based intraocular lenses (IOLs). First method is based on the analysis of the images formed by these IOLs in an optical bench (objective method). The second method are the results obtained with the Software Halo-v1.0 developed in the UGR of patients implanted with the same IOLs (psychophysical method). The third method is the subjective method, based on the answer of the patients to the specific question. IOLs included in the study were the bifocal Tecnis-1 of additions +4.0, +3.25, +2.75 and the trifocals AT.Lisa-tri and Finevision.

Setting:

1 - Optics and Optometry Faculty of Terrassa (UPC), Barcelona, Spain. 2 - “Área Oftalmológica Avanzada” (private clinic). Barcelona, Spain 3 - “IOA Madrid Innova Ocular” (private clinic). Madrid, Spain

Methods:

The objective characterization of the halo was performed using the images of a pinhole formed with each IOL in an optical bench with an artificial eye. Psychophysical method was carried-out by means of the Software Halo v1.0, one month after the surgery, monocularly, in the eye with better VA, in scotopic conditions (scoring 1 for no halo and 0 for lots of halo). Subjective observations of halos and disturbances were evaluated in each patient asking a specific question: “How do the halos affect you?” scoring from 1 to 5 (1 for high disturbances and 5 no disturbances).

Results:

The objective method revealed that, as predicted by a theoretical approximation, the halo size depends on the addition of the IOL. The higher addition, the larger halo. Trifocal lenses presented a “double-halo” for each observation conditions (distance, intermediate and near). The psychophysical and subjective methods included 50 patients (10 of each IOL, at the date of submission). The halo score using the Halo Software v1.0 show the dependence of the halo size with the addition, which is in general agreement with the objective method. Subjective method show that trifocal IOL affect less the visual function than bifocal lenses.

Conclusions:

Regarding the influence of the addition of the halo perception both, psychophysical and objective methods are in agreement. Trifocal lenses presented a double halo when tested in the optical bench that cannot be detected with the psychophysical method used. When patients were asked about the subjective perception of the halo, those implanted with trifocal lenses reported less discomfort than those implanted with bifocal IOLs. Analyzing the profiles of intensity of the halo using the objective method one can see that the energy distribution in the halo zone can play an important role in the subjective perception of discomfort

Financial Interest:

NONE