Randomized controlled clinical trial to evaluate different intraocular lenses for the surgical compensation of low to moderate-to-high regular corneal astigmatism during cataract surgery.

PURPOSE: To evaluate vector analysis, rotational stability, and visual outcomes after implantation of toric IOLs with low (<2.25 diopter [D]) toric values (Acrysof IQ SN6AT3 or SN6AT4) and moderate-to-high toric (3.00 D to 6.00 D) values (Acrysof IQ SN6AT5, SN6AT6, SN6AT7, SN6AT8, or SN6AT9) versus after implantation of a nontoric IOL (Acrysof SN60WF) in eyes with regular topographic corneal astigmatism.

SETTING: Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria.

DESIGN: Randomized controlled clinical trial.

METHODS: The study included eyes of patients undergoing phacoemulsification and IOL implantation. Patients were randomized into 3 groups to bilaterally receive the nontoric IOL, the low toric IOL, or the moderate-to-high toric IOL. Over a 6-week follow-up period, rotational stability and astigmatic changes were evaluated in the 2 toric IOL groups using the Alpins vector method.

RESULTS: The study included 78 eyes of 39 patients. Postoperatively mean refractive astigmatism decreased significantly from 1.45 D ± 1.18 (SD) to 0.36 ± 0.44 D in the low toric group and from 1.92 ± 1.09 D to 0.31 ± 0.46 D in the moderate-to-high toric group. There was no significant difference between mean difference vectors in the low toric IOL group and the moderate-to-high toric IOL group. A significant difference in the correction index was detected, revealing overcorrection with low toric IOLs (1.03 ± 0.12 D) and undercorrection with moderate-to-high toric IOLs (0.95 ± 0.12 D).

CONCLUSIONS: Implantation of low toric IOLs and medium-to-high toric IOLs in patients with low to moderate-to-high corneal astigmatism was shown to be effective in correcting regular corneal astigmatism. Undercorrection in the moderate-to-high group could be related to misalignment.

FINANCIAL DISCLOSURE: This research project was financially supported by the Fuchs Foundation for the Promotion of Research in Ophthalmology, Salzburg, Austria. Alcon Inc. financially supports the Fuchs-Foundation as the clinical research center of the Department of Ophthalmology of the Paracelsus Medical University Salzburg, Salzburg, Austria (Grant Number 2010-37). No author has a financial or proprietary interest in any material or method mentioned.