Evaluating Rotational Stability of the Visian V4b TICL in Patients with High Myopic Astigmatism.

INTRODUCTION

To evaluate the rotational stability of the Visian V4b toric implantable collamer lenses (TICLs) over a 12-month follow-up period and to assess refractive outcomes and potential factors associated with lens rotation at one U.S.

METHODS

This retrospective study included 48 eyes from 26 patients who underwent Visian TICL implantation between 2018 and 2021 at a single U.S. refractive surgical center. Eligible patients were ≥ 18 years old with myopia ranging from - 3.0 to - 20.0 D and astigmatism ranging from - 1.0 to - 4.0 D. Postoperative assessments were conducted at 1 week, 1 month, and 3, 6, and 12 months. Rotational stability was measured using standardized slit lamp photography with image overlay analysis. Visual acuity, refractive outcomes, and vault measurements were recorded at each visit. Vector analysis was performed, and potential factors associated with TICL rotation were analyzed using correlation analyses.

RESULTS

Mean (± standard deviation) implanted ICL sphere was - 11.4 ± 1.87 D, and mean implanted ICL cylinder was 2.00 ± 0.81 D. Of the implanted ICL sizes, the majority of eyes received a 13.2-mm ICL (26 eyes, 54.2%) and a 12.6-mm ICL (20 eyes, 41.7%). At 12 months, uncorrected distance visual acuity (UDVA) was 20/20 or better in 83% of eyes, with a safety index of 1.21 and an efficacy index of 1.04. The mean absolute rotation at 12 months was 6.26 ± 6.57°, with no significant change between follow-up visits (all P > 0.05). A significant correlation was found between absolute rotation and ICL sphere, however, no significant correlations were observed between absolute rotation and preoperative sphere, white-to-white distance, anterior chamber angle, postoperative vault, or ICL size. At 1 week postoperatively, clockwise rotation occurred more frequently than counterclockwise rotation (P = 0.004), with no significant difference in rotation direction thereafter.

CONCLUSION

Visian V4b TICLs demonstrate excellent visual and refractive outcomes with acceptable rotational stability over 12 months. Overall, TICLs remain a predictable option for the correction of moderate-to-high myopic astigmatism, with a low risk of clinically significant rotation.