Visual performance after implantation of Tecnis ZM900 and Rezoom multifocal intraocular lenses

Abstract

Objective To evaluate visual performance after implantation of either the Tecnis ZM900 multifocal intraocular lens (MIOL) or the Rezoom MIOL. Methods This was a prospective comparative clinical study that included 25 eyes of 22 patients implanted with Tecnis ZM900 MIOL and 15 eyes of 14 patients implanted with Rezoom MIOL. The following parameters were assessed 3 months after surgery: refraction and best corrected distance visual acuity, uncorrected distance,intermediate and near visual acuities, photopic and mesopic contrast sensitivity at different spatial frequencies, and spherical aberrations at different pupil diameters. The data were analyzed with independent samples t test. Results Both groups achieved good distance visual acuity. For intermediate visual acuity at 100 cm, the best corrected and uncorrected visual acuity for eyes implanted with Rezoom MIOL were better than those with Tecnis ZM900 MIOL (t=0.85, 2.50, 2.15,P＜0.05). There were no statistically significant differences between the two groups for visual acuities at 63 cm and 40 cm (t=1.55, 0.45, P＞0.05). However, eyes implanted with Tecnis ZM900 MIOL had better near visual acuity at 33 cm than those with Rezoom MIOL (t=5.52, P＜0.05). There were statistically significant differences in mesopic contrast sensitivity at low spatial frequencies (3, 6 c/d)between the two groups (t=2.15, 3.01, P＜0.05). The root mean square of spherical aberrations was lower in eyes with Tecnis ZM900 MIOL than those with Rezoom MIOL for 3, 4, and 5 mm pupil diameters (t=2.16, 2.28, 4.00, P＜0.05). There were no statistically significant differences in photopic contrast sensitivity between the two groups (t=1.94, 1.00, 0.60, 0.67, P＞0.05). Conclusion The RezoomMIOL provide better distance and intermediate visual acuity. The Tecnis ZM900 MIOL provide good distance and near visual acuity. The Tecnis ZM900 MIOL provide better contrast sensitivity at low spatial frequencies due to a significant reduction in spherical aberrations under mesopic conditions. Key words: Lenses,intraocular,multifocal; Visual acuity; Contrast sensitivity; Spherical aberration; Phacoemulsification