Ocular preference following implantation of aspheric and spherical intraocular lenses; an intra-individual comparison

Abstract

Purpose: Recently, intraocular lenses (IOLs) that possess an aspheric design, compensating for the spherical aberration (SA) of the cornea, have been developed. We designed this study to compare a group of patients who had undergone bilateral cataract surgery and had received one spherical IOL and one aspheric IOL, to assess their ocular preference. Methods: Patients were recruited from those who had undergone bilateral cataract surgery during the preceding six months (32 patients). Types of aspheric IOLs, which were used included: Tecnis ZA9003, AcrysofIQ SN60WF and Akreos Adapt AO. Contrast acuity was measured using a CSV-1000CVA instrument and spherical aberration (SA) was measured using a Zywave aberrometer. Patients also answered a brief questionnaire, designed to determine whether they could detect any difference between their spherical and aspheric IOLs and whether they had an ocular preference. Results: No differences were found between spherical and aspheric IOLs in contrast acuity. Total ocular spherical aberration was greater among eyes with spherical IOLs compared with aspheric IOLs (t = 6.67; p < 0.0001). Patients' ocular preference was unrelated to the presence of an aspheric IOL or the amount of spherical aberration, but was associated with the level of ametropia and visual acuity. Conclusions: We were unable to find any impact on a patient's subjective visual quality from a reduction of spherical aberration by the presence of an aspheric IOL. Ocular preference was determined by level of visual acuity and degree of ametropia post-operatively.