Functional Intermediate Vision and Pupil-Dependent Optical Behavior After Implantation of a Segmented Refractive Multifocal Intraocular Lens

Purpose: To evaluate functional visual outcomes, defocus characteristics, pupil-dependent intraocular higher-order aberrations (HOAs), and their interrelationships in eyes implanted with a segmented refractive multifocal intraocular lens (MIOL), a design intended to provide both near and intermediate visual function. Methods: This retrospective observational study included 88 eyes (64 patients) implanted with a segmented refractive MIOL (SBL-3) and a monofocal IOL (Akreos Adapt AO) as a reference. Postoperative functional visual acuity at distance, intermediate, and near was assessed. Distance-corrected defocus curves were obtained. Intraocular wavefront aberrations were measured under bright and dim lighting conditions, and pupil diameter was recorded. Correlation analyses were performed to explore the relationships between pupil diameter, intraocular HOAs, and intermediate visual acuity in the SBL-3 group. Results: Distance visual acuity did not differ significantly between groups. The SBL-3 group demonstrated significantly better uncorrected and distance-corrected intermediate and near visual acuity compared with the monofocal reference group. The defocus curve of the SBL-3 IOL showed a relatively smooth functional visual profile across intermediate defocus levels. Intraocular HOAs, particularly coma and trefoil, were significantly higher in the SBL-3 group and exhibited strong pupil-dependent behavior under both bright and dim conditions. However, no significant linear correlations were observed between intraocular HOAs and intermediate visual acuity. Conclusion: The segmented refractive multifocal IOL provided improved functional intermediate vision while exhibiting pupil-dependent increases in intraocular HOAs. These findings provide clinically relevant insights into the pupil-dependent optical behavior of segmented refractive MIOLs and suggest that increased HOAs may not necessarily compromise functional intermediate visual acuity.