To determine the size of a halo in the visual field induced by bright light after cataract surgery and implantation of an aspheric apodized diffractive multifocal intraocular lens (IOL) or aspheric monofocal IOL.Methods
This prospective observational study comprised 54 healthy eyes (mean age 72.6 ± 10.4) of 54 subjects having cataract surgery with bilateral implantation of an AcrySof ReSTOR SN6AD1 IOL (32 eyes, multifocal group) or AcrySof SN60WF IOL (22 eyes, monofocal group). Six months postoperatively, halo size was measured using the Vision monitor. Optotypes of low luminance (5cd/m2) were presented at a distance of 2.5 m. The visual angle subtended by the radius of the halo was calculated in minutes of arc (arc min). Best-corrected distance logMAR visual acuity (VA) was evaluated with high-contrast (HC-96%) and low-contrast (LC-10%) logMAR Bailey-Lovie letter charts.Results
The mean radius of the halo was 219.3 ± 42.1 and 194.0 ± 55.3 arc min (p > 0.05) in the multifocal and the monofocal groups respectively. The HC and LC VA means showed significant differences between the two groups, being worse in the multifocal group. Also, the HC and LC-VA exhibited a significant correlation with halo size (r= 0.52 y r= 0.57 respectively).Conclusion
Mean halo size was not significantly different between the multifocal ReSTOR SN6AD1 and the monofocal AcrySof SN60WF IOLs. Worse HC and LC-VA values were related to higher halo size measurements in the IOLs groups.