Comparison of Visual Performance between Refractive and Diffractive Multifocal Intraocular Lenses

Abstract

BACKGROUND: To compare the visual performance of asymmetric refractive multifocal intraocular lenses (MIOLs) with all optic zone diffractive MIOLs. METHODS: A prospective study. Patients underwent phacoemulsification were divided into two groups according to the type of MIOLs: 25 patients were implanted with asymmetric refractive MIOLs and 25 patients with all optic zone diffractive MIOLs. Visual acuity, refraction, defocus curves, objective optical quality and the questionnaire of life quality were measured 3 months after surgery. RESULTS: There was no significant difference between two groups in uncorrected distance visual acuity、uncorrected near visual acuity、best corrected distance visual acuity or distance corrected near visual acuity. However, the uncorrected intermediate visual acuity was 0.24±0.10 in refractive group and 0.31±0.13 in diffractive group (P<0.05); the distance corrected intermediate visual acuity was 0.22±0.09 in refractive group and 0.31±0.14 in diffractive group (P<0.05). Defocus curves showed two peaks of maximum vision in both groups. However, the curve between two peaks of refractive group was smoother than diffractive group. The Modulated transfer function cut-off frequency was （22.74±12.29）c/d in refractive group and（30.50±10.04）c/d in diffractive group (P<0.05); the OQAS values 100% (OV100%) were 0.75±0.41 in refractive group and 1.02±0.34 in diffractive group（P<0.05），OV20% were 0.52±0.34 in refractive group and 0.71±0.25 in diffractive group （P<0.05）.There was no significant difference between two groups at overall satisfaction, independence spectacles ratio or visual interference phenomenon. CONCLUSIONS: Both MIOLs achieve good visual acuity at distance and near. The asymmetric refractive MIOLs show better intermediate visual acuity, and the all optic zone diffractive MIOLs appear to have better objective visual quality.