Comparison of Optical Performances in Eyes Implanted With Aspheric and Spherical Intraocular Lenses After Cataract Surgery

ABSTRACT

PURPOSE: To compare optical performances in eyes implanted with aspheric and spherical intraocular lenses (IOLs) after cataract surgery. METHODS: In 88 eyes of 69 patients, spherical (Sensar AR40; Acrysof natural SN60AT) or aspherical (Tecnis ZA9003; Acrysof IQ SN60WF) IOLs were implanted. After one month, contrast sensitivity, depth of focus, and spherical aberration were measured and compared between the groups. RESULTS: Contrast sensitivities of ZA9003 and SN60WF were significantly higher in 12,18 cycles per degree (CPD) under photopic conditions and were also higher in 6,12,18 CPD under mesopic conditions compared to those of respective spherical IOLs. Depths of focus were 1.31 D in ZA9003, 1.67 D in SN60WF, 1.52 D in AR40, and 1.49 in SN60AT, and the differences were not significant. Spherical aberration (Z40) with a 4 mm pupil was -0.032 microm in ZA9003, 0.022 microm in SN60WF, 0.076 microm in AR40, and 0.072 microm in SN60AT. Spherical aberration of SN60WF was significantly lower than spherical IOLs, and that of ZA9003 had the lowest among all IOL groups. Depth of focus significantly correlated with spherical aberration. CONCLUSIONS: Aspheric IOLs were superior in mesopic contrast sensitivity and equal in depth of focus to spherical IOLs. Individual corneal spherical aberration should be considered in the choice of IOLs.