Correlation between pupillary size and intraocular lens decentration and visual acuity of a zonal-progressive multifocal lens and a monofocal lens

Objective: To see whether there is a correlation between pupillary area or intraocular lens (IOL) decentration and tilt and the visual acuity (VA) at all distances for eyes with a zonal-progressive multifocal IOL or a monofoc al IOL. Design: Comparative, nonrandomized, interventional study. Participants: Fifty-five eyes of 55 patients undergoing five-zone refractiv e multifocal IOL implantation and 55 eyes of 55 age-matched patients underg oing monofocal IOL implantation. Intervention: All eyes underwent phacoemulsification and IOL implantation. Main Outcome Measures: The VAs from far to near distances were examined usi ng an all-distance vision tester at 1 month after surgery. The pupillary ar ea was also measured using an infrared pupillometer, and the degrees of IOL decentration and tilt were measured using a Scheimpflug videophotography s ystem. Univariate associations between VA and the pupillary area and IOL de centration or tilt were evaluated statistically. Results: The mean intermediate VAs and contrast sensitivities at all spatia l frequencies in the multifocal IOL group were worse than those in the mono focal IOL group, whereas near VA was better in the multifocal group. In the multifocal group, smaller pupillary area was associated significantly with worse near logarithm of the minimum angle of resolution (LogMAR) VA (r=0.6 36), but not with far or intermediate VAs. When pupil diameter was 4.5 mm o r greater, near mean VA reached 20/63. A greater degree of IOL decentration was associated significantly with worse far and intermediate LogMAR VAs (r =0.460 at 5.0 m and 0.527 at 1.0 m) but not with near VA. When decentration was 0.9 mm or greater, distance mean VA did not reach 20/32. However, the correlation between tilt and VA was not statistically significant. In the m onofocal group, no significant correlation was found between pupillary area , IOL decentration, or tilt and the VA. Conclusions: Smaller pupil size is correlated significantly with worse near VA, whereas greater decentration is correlated with worse distance and int ermediate VA in eyes with refractive multifocal IOLs. Specifically, a pupil diameter of less than 4.5 mm cannot provide useful near VA, and decentrati on of 0.9 mm is the maximum allowable limit for adequate distance VA. Howev er, pupil size and IOL decentration do not influence VA in eyes with monofo cal IOLs. Ophthalmology 2001;108:2011-2017 (C) 2001 by the American Academy of Ophthalmology.