[Spherical aberration influence in visual function after cataract surgery: prospective randomized trial]

We compare the contrast sensitivity and visual acuity obtained with an anterior surface modified prolate intraocular lens (Tecnis Z9000) with the contrast sensitivity and visual acuity obtained with a standard acrylic foldable intraocular lens (Acrysof SA60 AT).

In this prospective trial, 64 patients presenting for cataract surgery were randomized to receive in both eyes either the Tecnis Z9000 intraocular lens or the the Acrysof SA60AT intraocular lens: 32 Tecnis Z9000 and 32 Acrysof SA60AT. Visual acuity and contrast sensitivity were monocular and binocularly tested in all of them preoperatively and three months after surgery.

The Tecnis Z9000 intraocular lens provided statistically significantly better monocular (Tecnis group: 0.85; Acrysof group: 0.78; p < 0.01) and binocular (Tecnis group: 0.95; Acrysof group: 0.86; p < 0.02) visual acuity. The contrast sensitivity mean was also greater in Tecnis group in monocular and binocular conditions, but without statistical signification.

Visual acuity and contrast sensitivity after cataract surgery improved in both groups. But monocular and binocular visual acuity was statistically significantly better only in Tecnis group. The contrast sensitivity mean values were greater in Tecnis group but without statistically significant differences.