Comparison of two multifocal intraocular lens designs that differ only in near add

PURPOSE: To evaluate monocular functional outcomes after the implantation of the AcrySof ReSTOR SN6AD2 intraocular lens (IOL) (+2.5 diopters [ D] near add) (Alcon Laboratories, Inc., Fort Worth, TX) and the AcrySof ReSTOR SN6AD1 IOL (+3.0 D near add) (Alcon Laboratories, Inc.).METHODS: This prospective, comparative, nonrandomized single-blind observational study comprised 62 eyes of 62 patients that underwent phacoemulsification and implantation of a multifocal IOL: SN6AD2 (31 eyes) (+2.5 group) and SN6AD1 (31 eyes) (+3.0 group). Twelve months after surgery, monocular near (30 and 40 cm), intermediate (50, 60, and 70 cm), and distance (4 m) visual acuity were evaluated with the internal root mean square and modulation transfer function. Both parameters were evaluated at the 4-and 6-mm pupil sizes.RESULTS: No statistical differences at 4 m were found between the groups. The +2.5 group obtained better performances at all intermediate distances (50 cm, 0.23 +/- 0.14 vs 0.32 +/- 0.13; 60 and 70 cm, 0.21 +/- 0.10 vs 0.41 +/- 0.14 and 0.24 +/- 0.10 vs 0.53 +/- 0.17, respectively), whereas the near visual acuity was better for the + 3.0 group (30 and 40 cm, 0.36 +/- 0.18 vs 0.14 +/- 0.09 and 0.36 +/- 0.19 vs 0.17 +/- 0.07, respectively). The root mean square was lower for the +2.5 group compared to the +3.0 group, whereas the modulation transfer function showed overlapping results between the two models.CONCLUSIONS: Both IOL models showed good results in distance vision; the +2.5 D IOL seemed to provide better intermediate vision than the +3.0 D IOL. For near vision, the +3.0 D model performed better than the +2.5 D model.