Visual function after aspheric multifocal intraocular lenses implantation

Abstract

Objective To evaluate visual quality and pseudoaccommodation in patients after the implantation of an apodized diffractive aspherical multifocal intraocular lens (MIOL). Methods This was a prospective case series study. Thirty-five patients (50 eyes)who had agreed to undergo phacoemulsification and accept IOL implants were selected for the study. Any other eye disease or systemic disease was criteria for exclusion. The eyes were divided into 2 groups according to the type of IOL implanted. One group was implanted with apodized diffractive aspherical MIOL (AcrySof ReSTOR SN6AD3) and the other group was implanted with apodized diffractive MIOL (AcrySof ReSTOR SN60D3). Twenty-five eyes of 17 patients were implanted with SN6AD3 and 25 eyes of 18 patients were implanted with SN60D3. All patients were assessed 3 months postoperatively for aberrations of the crystalline lens, the modulation transfer function, uncorrected distance visual acuity (UCDVA), uncorrected near visual acuity (UCNVA), best corrected distance visual acuity (BCDVA), distance corrected near visual acuity (DCNVA), pseudoaccommodation,contrast sensitivity and the rate of eyeglass removal for near. Data were compared using an independent samples t test and x2 test. Results UCDVA, BCDVA, UCNVA and DCNVA in the SN6AD3 group were not statistically different from the SN60D3 group (P＞0.05). There were statistical differences between the two groups when spherical, 4th-order higher aberrations and total higher-order aberrations were compared. The SN6AD3 group had lower aberrations than the SN60D3group under 3 and 5 mm pupils. There were statistical differences in the MTF for spatial frequencies of 5, 10, 15, 20, 25 and 30 c/d. For these spatial frequencies, the SN6AD3 group had higher scores than the SN60D3 group. Accommodative range was (0.925±0.549)D in the SN6AD3 group and (0.964 ±0.582)D in the SN60D3 group. There were no statistically significant difference in accommodative range between the SN6AD3 and SN60D3 groups (t=0.217, P＞0.05). There were statistical differences in contrast sensitivity for spatial frequencies of 3, 6, 12 and 18 c/d. At these spatial frequencies, the SN6AD3 group had better contrast sensitivity than the SN60D3 group. The rate of eyeglass removal for near for the two MIOL groups was 80% and 72% (x2=0.439, P=0.508).Conclusion The AcrySof ReSTOR apodized diffractive aspherical MIOL provides excellent distance and near visual acuity, pseudoaccommodation and higher contrast sensitivity. Key words: Lenses,intraocular,multifocal; Aberrations; Accommodation; Modulation transfer function; Contrast sensitivity; Phacoemulsification