R. W. Bowman

A comparison of higher order aberrations in eyes implanted with AcrySof IQ SN60WF and AcrySof SN60AT intraocular lenses

Purpose. To evaluate the efficacy of AcrySof SN60WF aspheric intraocular lens (IOL) in decreasing spherical aberration and total higher order aberrations (HOAs) after cataract surgery compared to the spherical SN60AT lens. Methods. Wavefront analysis was conducted on 28 eyes of 28 patients that underwent uncomplicated phacoemulsification with implantation of either SN60WF (15 eyes) or SN60AT lenses (13 eyes). Eyes with a history of uveitis, retinal diseases, and previous surgery were excluded. Results. SN60WF eyes had less mean absolute spherical aberration than SN60AT eyes both at 4 mm (0.04±0.03 vs 0.11±0.03 RMS, p<0.0001) and 6 mm pupils (0.09±0.04 vs 0.43±0.12 RMS, p<0.0001). Mean total HOAs was lower in the SN60WF group at 6 mm pupils (0.44±0.14 vs 0.56±0.13 RMS, p=0.0274), while no difference was seen at 4 mm pupils (0.20±0.10 vs 0.25±0.08 RMS, p=0.160). There were no clinically significant differences between the SN60WF and SN60AT IOLs both at 4 and 6 mm pupils in terms of coma (0.16±0.07 vs 0.18±0.09 RMS, p=0.514 and 0.25±0.12 vs 0.23±0.12 RMS, p=0.664) and trefoil (0.14±0.09 vs 0.10±0.05 RMS, p=0.167 and 0.28±0.12 vs 0.23±0.07 RMS, p=0.199). There were no differences between groups in mean age, axial length, postoperative spherical equivalent, IOL power, or corneal curvature. Conclusions. An aspheric posterior optic IOL design with thinner center effectively reduces the positive ocular spherical aberration observed in the pseudophakic and elderly eyes, especially at larger pupillary diameters (6 mm), with no notable increase in coma. However, reduction in total ocular HOAs was only significant at 6 mm pupils.