Comparison of refractive stability after non-toric versus toric intraocular lens implantation during cataract surgery.

Abstract

PURPOSE: To compare refractive state changes in eyes implanted with toric intraocular lenses (IOLs) vs non-toric IOLs, after cataract extraction.

DESIGN: Retrospective, comparative.

METHODS: In a single institution, 121 eyes underwent phacoemulsification and implantation with either non-toric IOLs or toric IOLs. The spherical value, cylindrical value, spherical equivalent (SE) of refractive error, and visual acuity were measured preoperatively and 1, 3, and 6 months after surgery. Main outcome measures were the pattern of changes of spherical, cylindrical, and SE values based on postoperative time, between different IOL types.

RESULTS: The groups, which included patients who underwent surgery with SN60WF (Group I), SA6AT3 (Group II-3), SA6AT4 (Group II-4), and SA6AT5 lenses (Group II-5), contained 37, 29, 23, and 32 eyes, respectively. The cylindrical value was significantly decreased in all groups (P < .05). Before surgery, the SE of refractive errors was estimated as -0.21, -0.10, -0.20, and -0.22 in the respective groups. The actual remaining SE values were -0.19, -0.24, -0.42, and -0.56 at 1 month; -0.17, -0.26, -0.57, and -0.64 at 3 months; and -0.17, -0.26, -0.70, and -0.74 at 6 months postoperatively, respectively. The follow-up SE values in groups I and II-3 were similar (P > .05 in both groups); however, significant myopic changes were observed in Groups II-4 and II-5 after surgery, vs Group I (P < .05).

CONCLUSION: Selection of toric IOLs for cataract surgery requires a refined formula to precisely determine necessary IOL power, especially in cases with high levels of astigmatism, to reliably and accurately prevent myopic outcomes.