Comparison of higher-order aberration and contrast sensitivity in monofocal and multifocal Intraocular lenses

Purpose: The visual performance of pseudophakic eyes depends on the type of intraocular lenses (IOLs) that are implanted. Aspherical and multifocal IOLs have recently been developed to improve visual quality after cataract surgery, but multifocal IOU can be associated with decreased contrast sensitivity (CS), halos, and glare. This study compares the visual performance of monofocal and multifocal IOLs by measurement of higher-order aberrations (HOAs) and CS values. Materials and Methods: HOAs and CS values of 42 eyes with implanted monofocal IOLs and 40 eyes with implanted multifocal IOLs were measured preoperatively and more than 6 months after surgery. In the multifocal IOL group, HOAs and CS values were also measured with addition of a trial lens of -0.5 diopter (D) to evaluate the compensatory effect on spherical aberration. Results: CS values of the multifocal IOL group were significantly lower than those of the monofocal IOL group for all spatial frequencies tested (p < 0.01), and the spherical aberration was significantly higher in the multifocal IOL group than in the monofocal IOL group (p < 0.001). Addition of a -0.5 D lens to the multifocal IOL group decreased the difference in CS between the two groups (p = 0.003). Conclusion: Increased spherical aberration may contribute to lower CS in the multifocal IOL group. In such cases, CS can be improved by addition of a - 0.5 D lens to compensate for the spherical aberration.