Predictability and Vector Analysis of Laser in Situ Keratomileusis for Residual Errors in Eyes Implanted with Different Multifocal Intraocular Lenses

Purpose: To investigate potential differences in predictability, efficacy, and safety of corneal excimer laser to correct residual myopia, hyperopia, and astigmatism in eyes previously implanted with multifocal intraocular lenses using distinct optical surfaces and platforms for multifocality. Methods: This prospective comparative study included 37 eyes submitted to laser in situ keratomileusis correction for residual errors after implantation of either an apodized diffractive-refractive (Restor) or a full-diffractive (Tecnis) multifocal intraocular lens. Data analysis included investigation of predictability, efficacy, and safety of excimer laser surgery to correct residual errors. A double-angle plot, using vector analysis, was also created to evaluate predictability of astigmatism correction. Results: At 6-month follow-up, statistical analyses revealed a significant improvement when comparing preoperative (0.51 ± 0.25 and 0.44 ± 0.18) and postoperative values (0.17 ± 0.10 and 0.09 ± 0.07) of uncorrected distance visual acuity (P < 0.0001 and <0.0001), preoperative (0.92 ± 0.61 and 1.02 ± 0.45) and postoperative values (0.33 ± 0.23 and 0.19 ± 0.17) of manifest refractive spherical equivalent (P 0.0006 and <0.0001), and preoperative (-1.08 ± 0.70 and -0.65 ± 0.42) and postoperative values (-0.25 ± 0.28 and -0.14 ± 0.21) of astigmatism (P < 0.0001 and <0.0001) in eyes implanted with Restor and Tecnis, respectively. Vector analysis revealed a predictable correction of astigmatism in all groups. Ninety-two percent of total eyes achieved a manifest refractive spherical equivalent within ±0.5 of emmetropia. Conclusions: Corneal excimer laser refractive surgery seems to be equally effective to correct different residual errors, including astigmatism, in eyes implanted with intraocular lenses with various platforms for multifocality.