Objective: To evaluate the visual performance after implantation of the Tecnis ZM900 multifocal intraocular lens (IOL) (TMF) and the Restor SA60D3 multifocal IOL (Restor).
Methods: In a prospective study, TMF or Restor was implanted randomly in 73 patients (90 eyes). The following parameters were assessed 3 months after surgery: refraction, uncorrected and best corrected visual acuities (VA) for distance, intermediate, near and different contrast levels, reading ability, pupil size, wave-front error, defocus curve and position of IOL. Patient satisfaction (overall satisfaction, spectacle independence, photic phenomena) was assessed by a questionnaire. The chi-square test was applied to compare categorical variables and Mann-Whitney U test was used to compare the measured data.
Results: The uncorrected, best corrected and/or distance-corrected VA for distance, intermediate, near and different contrast levels did not show statistically significant differences between the two groups (P > 0.05). Near reading acuity and reading speed were better in TMF under low-light conditions (Z = -2.579, P = 0.009; Z = -5.244, P = 0.000). The curve of defocus showed that TMF had significantly better intermediate distance (at 50 cm) (Z = -5.300, P = 0.000) and worse near distance (from 25 to 28 cm) than those of Restor (Z = -3.745, P = 0.000; Z = -5.691, P = 0.000). Measurements under pupil diameter at 3.0 mm and 5.0 mm, ocular and intraocular Z (4, 0) were significantly lower (Z = -8.175, P = 0.000; Z = -5.210, P = 0.000 and Z = -4.453, P = 0.000; Z = -3.790, P = 0.000), the values of PSF Strehl Ratio and MTF AreaRatio A/D were significantly higher (Z = -3.047, P = 0.002; Z = -3.672, P = 0.008 and Z = -2.038, P = 0.042; Z = -2.579, P = 0.009) in TMF than those in Restor. On the questionnaire, there was no difference of overall satisfaction, spectacle independence and photic phenomena (P > 0.05).
Conclusions: Implantation of the TMF and Restor offers excellent distant and near VA. Restor had better near VA than that of TMF based on the curve of depth, TMF had better VA at 50 cm-distance. Reading speed is faster in TMF. Compared to spherical Restor, TMF provides a better quality of vision due to a negative spherical aberration.