[Clinical comparison study of aspheric and spherical intraocular lenses]

To compare spherical aberration and visual quality in pseudophakic patients with a modified prolate aspheric intraocular lens (IOL) with patients with a spherical IOL.

A prospective study of 169 consecutive cases (169 eyes) was conducted. All cataract patients underwent phacoemulsification were randomized to receive an aspheric IOL or a spherical IOL. The following investigations were performed to assess the spherical aberrations of total eye and cornea, best corrected visual acuity (BCVA), near visual acuity (NVA), contrast sensitivity, glare sensitivity and apparent accommodation.

The mean spherical aberration in eyes with a Tecnis IOL [(0.024 +/- 0.076) microm] was significantly lower than that of eyes with a spherical IOL [(0.217 +/- 0.137) microm, P = 0.000]. In addition, Tecnis IOL provided improved contrast sensitivity at 4.0 degrees (39.18 +/- 11.94 versus 33.28 +/- 11.84, P = 0.009) and 2.5 degrees (28.30 +/- 12.07 versus 24.50 +/- 8.20, P = 0.033) visual angles, and improved glare sensitivity at 6.3 degrees (30.90 +/- 9.21 versus 27.08 +/- 8.24, P = 0.022), 4.0 degrees (27.09 +/- 8.45 versus 23.30 +/- 6.24, P = 0.008), 2.5 degrees (19.20 +/- 8.71 versus 15.53 +/- 4.37, P = 0.005) and 1.6 degrees (12.08 +/- 4.44 versus 10.04 +/- 4.20, P = 0.014) visual angles. The difference of BCVA, NVA and apparent accommodation between these two groups was not significant.

The present clinical results demonstrated that an aspheric IOL may reduce the spherical aberration and improve visual performance of pseudophakic eyes as compare to conventional spherical IOL.