Effect of decentration on the optical performance in multifocal intraocular lenses.

Aims: To evaluate the influence of decentration on optical performance in multifocal intraocular lenses (IOLs) using eye models.

Methods: This study evaluated 4 types of multifocal IOLs (ReSTOR SA60D3, Alcon; TECNIS Multifocal ZM900, AMO; ReZoom, AMO; SFX-MV1, Hoya). The evaluations were based on measurements of the near and far modulation transfer function (MTF) and visualized actual near images (newspaper) using eye models with the IOL horizontally displaced 0, 0.25, 0.5, 0.75 and 1.0 mm from the center.

Results: For the diffractive ReSTOR the near MTF decreased with increasing decentration. The near images (newspaper characters) became difficult to distinguish at a decentration of 1.0 mm. For the diffractive ZM900, the near and far MTFs gradually decreased with increasing decentration. For the refractive ReZoom and SFX-MV1, we observed almost no change in the near MTF from a decentration of 0-1.0 mm. However, the far MTF clearly decreased starting at a decentration of 1.0 mm for ReZoom and 0.75 mm for SFX-MV1.

Conclusion: The MTFs and near images are affected to a different extent depending on the design of multifocal IOLs; clinically relevant effects are not to be expected up to a decentration of 0.75 mm.