Depth of focus in eyes with diffractive bifocal and refractive multifocal intraocular lenses

PURPOSE: To evaluate monocular and binocular depth of focus in eyes with different multifocal intraocular lens (IOLs) systems. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: In this comparative interventional study, binocular implantation of multifocal IOLs was performed in 3 groups. In the first group, 26 eyes of 13 patients received asymmetric Acri.Twin (Acri.Tec) IOLs, a near-weighted 733D in 1 eye and a distance-weighted 737D in the fellow eye. In the second group, 26 eyes of 13 patients received a diffractive 811 E IOL (Pharmacia). In the third group, 26 eyes of 13 patients received a refractive Array IOL (AMO). The visual acuity was tested monocularly and binocularly starting at 6 m in 0.50 diopter (D) defocusing steps. RESULTS: Distance visual acuity was best in eyes with the distance-dominated 737D IOL; eyes with the other IOLs had comparable results. Binocular distance visual acuity was comparable between the Acri.Twin group and the 811 E group. The Acri.Twin group had better distance visual acuity than the Array group (P <=.048). Near visual acuity was best in eyes with the near-weighted 733D, followed by the 737D and the 811 E. Patients with Array IOLs had worse visual acuities at reading distance (between 33 cm and 40 cm) (P <=.001). Patients with diffractive bifocal IOLs had better results than patients with refractive multifocal IOLs at reading distance (P <=.018). CONCLUSION: The diffractive IOLs performed better than refractive IOLs. Asymmetric-weighted IOLs provided better binocular depth of field.