Wavefront analysis and modulation transfer function of three multifocal intraocular lenses

Abstract

Purpose:To evaluate wavefront performance and modulation transfer function (MTF) in the human eye after the implantation of diffractive or refractive multifocal intraocular lenses (IOLs).Materials and Methods:This was a prospective, interventional, comparative, nonrandomized clinical study. Uncorrected distance and near visual acuity, and wavefront analysis including MTF curves (iTrace aberrometer, Tracey Technologies, Houston, TX, USA) were measured in 60 patients after bilateral IOL implantation with 6 months of follow-up. Forty eyes received the diffractive ReSTOR (Alcon), 40 eyes received the refractive ReZoom (Advanced Medical Optics) and 40 eyes, the Tecnis ZM900 (Advanced Medical Optics). The comparison of MTF and aberration between the intraocular lenses was performed using analysis of variance (ANOVA), followed by the Dunn test when necessary.Results:The mean uncorrected distance visual acuity was similar in all three groups of multifocal IOLs. The ReSTOR group provided better uncorrected near visual acuity than the ReZoom group (P < 0.001), but similar to the Tecnis group. Spherical aberration was significantly higher in the ReZoom group (P = 0.007). Similar MTF curves were found for the aspheric multifocal IOL Tecnis and the spheric multifocal IOL ReSTOR, and both performed better than the multifocal IOL ReZoom in a 5 mm pupil (P < 0.001 at all spatial frequencies).Conclusions:Diffractive IOLs studied presented similar MTF curves for a 5 mm pupil diameter. Both diffractive IOLs showed similar spherical aberration, which was significantly better with the full-diffractive IOL Tecnis than with the refractive IOL ReZoom.

Clinical Outcomes Following Implantation of Diffractive Multifocal Intraocular Lenses With Varying Add Powers

“…Spherical aberration in eyes with the ZM900 was significantly lower than in eyes with other multifocal IOLs, including both refractive and diffractive multifocal IOLs. 16 Compared to monofocal IOLs, spherical aberration of the ZMA00 was comparable to the TECNIS monofocal IOL and significantly better than spherical monofocal IOLs. 17 Contrast sensitivity improvements following ZM900 implantation were statistically significant across all stimulus spatial frequencies examined.…”

Internal spherical aberration by ray tracing-type aberrometry in multifocal pseudophakic eyes

“…This aberrometer was already used in several studies. [24][25][26][27] Furthermore, some studies reported the comparability and repeatability of ray tracing aberrometers with good results. [28][29][30][31][32] However, no previous study measured the aberration of multifocal IOLs using a ray tracing-type aberrometer.…”

Modulation transfer function and optical quality after bilateral implantation of a +3.00 D versus a +4.00 D multifocal intraocular lens

“…Commercial wavefront sensors assume that this constant provides a smooth, continuous wavefront. 25 Because in theory multifocal IOLs provide 2 emergent wavefronts, it is reasonable to ask which wavefront the aberrometer device actually obtains and measures. As Charman et al 26 discussed, if there is a point source on the patient's retina, as provided for example in a Hartmann-Shack aberrometer, theoretically 2 wavefronts will emerge from the eye; that is, a regular (flat) wavefront produced by the distance correction and a converging spherical wavefront produced by the diffractive near addition.…”