Refractive And Visual Outcome Of Misaligned Toric Implantable Collamer Lens After Operative Realignment

To evaluate and compare the refractive and visual outcomes of patients with misaligned toric implantable collamer lens (ICL) after operative realignment, with and without back-calculation of the toric axis after implantation of toric ICL.

retrospective case-control study

This retrospective case series included 40 eyes of 33 patients who underwent a second procedure for toric ICL realignment between December 2016 and June 2025. The ideal toric axis for the realignment procedure was calculated using a dedicated back-calculator tool (http://vectorcalc-wz.cn). Data collected and analyzed included patient demographics (age, gender), preoperative axal length, preoperative refraction, ICL size, and postoperative outcomes including residual refractive error and visual acuities. 

The mean postoperative toric ICL misalignment prior to the second surgery was 20.55 ± 19.01 degrees. Following rotational realignment, UDVA improved from -0.25±0.15 logMAR preoperatively to 0.06±0.03 logMAR postoperatively, with corresponding reduction in both residual sphere and cylinder. The postoperative UDVA when performing alignment to the original preoperative axis (50%) was 0.048±0.04 logMAR with a cylinder of 0.49±0.17 diopter (D). In the group with alignment to a back-calculated axis (50%), the CDVA was 0.075±0.018 logMAR with a cylinder of 0.16±0.15 D. High cylinder power ICLs (≥2D) showed a higher decrease in residual cylinder when back-calculation was performed than low cylinder power ICLs (< 2D). 

Realignment of misaligned toric ICL improves visual acuity and reduces residual refractive errors. Especially for high cylinder power ICL, better refractive outcome can be seen when performing a back-calculation before realignment.