Effect of preoperative corneal astigmatism orientation on results with a toric intraocular lens

PURPOSE: To compare the Acrysof IQ toric intraocular lens (IOL) and the Acrysof IQ aspheric nontoric IOL and evaluate the effect of preoperative corneal astigmatism orientation on results. SETTING: Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan. DESIGN: Comparative case series. METHODS: This retrospective chart review comprised patients with cataract and preoperative corneal astigmatism between 1.0 diopter (D) and 2.5 D having toric IOL (toric group) or aspheric nontoric IOL (nontoric group) implantation. Eyes were grouped depending on the preoperative axis of corneal astigmatism; that is, with the rule (WTR), against the rule (ATR), and oblique. Preoperative and postoperative analyses included uncorrected (UDVA) and corrected (CDVA) distance visual acuities and cylindrical power preoperatively and 3 months postoperatively. RESULTS: The postoperative CDVA was not significantly different between the 2 IOLs; however, the postoperative UDVA was significantly better in the toric group than in the nontoric group (P<.0001). The postoperative residual cylindrical power was significantly smaller in the toric group (P<.0001). In eyes with ATR and oblique astigmatism, the mean postoperative UDVA was significantly better in the toric group, whereas there were no differences between the 2 groups in patients with WTR astigmatism. CONCLUSIONS: There was significant improvement in postoperative cylinder and UDVA with toric IOLs compared with nontoric IOLs. With a superior corneal incision, the benefits of astigmatism correction with the toric IOL were more significant in patients with ATR and oblique astigmatism than in those with WTR astigmatism.