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.