Analysis of the vision quality after implantation of the aspherical intraocular lens with partly or all eliminating the corneal spherical aberration

Abstract

Objective To compare the vision quality after implantation of the Tecnis ZA9003 aspheri-cal intraocular lens (IOL) between patients with a preoperative corneal spherical aberration of at least 0.33μ m and patients with a preoperative corneal spherical aberration less than 0.33μ m. Methods The corneal spheri-cal aberration with 6 mm aperture of 60 eyes (48 patients) was measured with a iTrace Visual Function Ana-lyzer 1 day before surgery, all the patients were divided into the test group and the control group according to their preoperative corneal spherical aberration of at least 0.33μ m or less than 0.33μ m. Tecnis ZA9003 aspher-ical IOL was implanted after phacoemulsification through a clear-cornea, 3.2 mm incision without suture.Un-corrected visual acuity, best corrected visual acuity (BCVA), contrast sensitivity, total wavefront aberration and modulation transfer function (MTF) at six spatial frequencies were examined at 3 months postoperatively.Results The postoperative spherical aberration of the eye at 6 mm pupil diameter was larger in the test group (0.088±0.046μm) than in the control group (-0.038±0.062μ m) (P 0.05). Patients in the test group had better contrast sensitivity than those in the control group. Statistically significant differences were detected at spatial frequencies of 3.0 cycles per degree (cpd) under mesopic conditions without glare and at 1.5cpd and 6cpd un-der mesopic conditions with glare (P<0.05). The values of MTF in the test group were higher than the control group at all spatial frequencies in 3.0mm and 6.0 mm pupil sizes (P<0.05). Conclusions Targeting for a postoperative small amount of positive spherical aberration after implantation of aspherical IOL may improve the vision quality of patients. Key words: Phacoemulsification; Aspherical intraocular lens; Aberration; Visual quality