Toric versus Standard Implantable Collamer Lens Implantation for Low Myopic Astigmatism: A 12-Month Retrospective Study.

Abstract

Background: Implantable collamer lens (ICL) and toric ICL (TICL) have shown effectiveness for myopic and astigmatic patients. This study aims to compare the visual and refractive outcomes of TICL and ICL implantation for low myopic astigmatism.

Methods: This single-center, retrospective, non-consecutive, and non-randomized study included 124 eyes of 124 patients with low myopic astigmatism who underwent TICL or ICL implantation. Visual acuity, refractive outcomes, visual quality, and ocular parameters were assessed at baseline, 3 months, and 12 months postoperatively. The surgical results were reported using standard graphs and double-angle astigmatism vector analysis.

Results: Both groups demonstrated excellent safety (TICL: 1.28±0.18; ICL: 1.19±0.16) and efficacy (TICL: 1.21±0.19; ICL: 1.09±0.16), with high predictability for spherical equivalent refraction (R ² of 0.980 and 0.984, respectively) and stable refractive outcomes at 12 months. UDVA was marginally better in the TICL group (-0.08±0.07 vs -0.03±0.06, p<0.001). Crucially, TICL yielded significantly lower residual astigmatism (-0.16±0.28 D vs -0.33±0.40 D, p < 0.05) and a smaller prediction error on vector analysis. Despite these refractive differences, objective visual quality metrics improved significantly in both groups, with no statistically significant intergroup differences observed.

Conclusions: Both TICL and ICL are safe and effective for low myopic astigmatism (0.75-1.0 D). Although TICL yielded significantly lower residual astigmatism and higher uncorrected visual acuity than ICL, the nonrandomized design and selection bias necessitate caution in claiming comparative superiority. Toric correction for such low astigmatism should be individualized, integrating clinical benefits with economic and safety factors.