Visual acuity tolerance to residual refractive errors in patients with an apodized diffractive intraocular lens

PURPOSE: To assess visual acuity tolerance to defocus caused by residual refractive errors after clear lens extraction (CLE) with apodized diffractive intraocular lens (IOL) implantation. SETTING: Fernandez-Vega Ophthalmological Institute, Oviedo, Spain. METHODS: In this prospective study, 150 eyes of 75 consecutive patients who had bilateral CLE with implantation of an AcrySof ReSTOR Natural IOL (Alcon) were evaluated. The eyes were divided into 2 groups: myopia and hyperopia. Residual refractive errors were analyzed using vector analysis. Monocular and binocular uncorrected distance visual acuity, best corrected distance visual acuity, uncorrected distance near visual acuity, and best distance-corrected near visual acuity 6 months after surgery were recorded. RESULTS: When the distance residual refractive error was corrected, there was a statistically significant improvement in uncorrected distance acuity in the myopia group and hyperopia group (P<.001). No differences were found between uncorrected-distance near acuity and best distance-corrected near acuity (P>.2). A significant trend toward worse visual acuity as a function of spherical equivalent (SE) value was significant only for uncorrected distance acuity (P<.001). No significant correlations were found for best corrected distance acuity, uncorrected-distance near acuity, and best distance-corrected near acuity as a function of SE (P>.2). CONCLUSIONS: Correction of distance residual refractive error improved distance visual acuity in patients with apoclized diffractive IOLs. However, near visual acuity was maintained whether the residual refractive error was corrected or not.