iTrace Toric Check for Monitoring Rotational Stability after EVO-TICL Implantation: A Prospective Case Series

Purpose: To evaluate the accuracy, clinical utility, and decision-guiding value of the iTrace Toric Check in detecting postoperative toric Implantable Collamer Lens (TICL) axis rotation, and to assess its correlation with manifest refraction cylinder outcomes.

Methods: Thirty-seven eyes of 22 patients with moderate-to-high myopic astigmatism underwent EVO-TICL (STAAR Surgical) implantation in this prospective, single-centre case series. The iTrace Toric Check was performed at 1 day, 1 week, 1 month, and 3 months postoperatively without pupil dilation. The detected axis deviation (in degrees) was correlated with residual manifest refractive cylinder, uncorrected distance visual acuity (UDVA), and best-corrected distance visual acuity (CDVA). Vector analysis was performed using the Alpins method. Rotational stability over time was assessed by one-way ANOVA.

Results: Mean preoperative spherical equivalent was −8.94 ± 2.83 D (range: −4.75 to −14.50 D) and mean preoperative refractive cylinder was −2.16 ± 0.91 D. At 3 months, mean UDVA was 0.06 ± 0.08 logMAR and mean residual refractive cylinder was −0.38 ± 0.29 D. The iTrace Toric Check detected a mean absolute axis deviation of 3.21 ± 2.44° (range: 0–11°) at 3 months. Deviation was greatest in the first postoperative week (mean 4.87 ± 3.12°) and stabilised significantly thereafter (p = 0.003). A total of 27 eyes (73.0%) showed 10° deviation at 1 week and underwent successful iTrace-guided repositioning. No eye required repositioning beyond 1 month.

Conclusion: The iTrace Toric Check allows objective, dilation-free monitoring of post-TICL rotational stability in routine clinical practice. Axis deviation correlated strongly with residual refractive cylinder, and all eyes needing repositioning were identified at the scheduled 1-week visit, before patients reported symptoms. Routine inclusion of the iTrace Toric Check in post-TICL follow-up protocols is recommended.