Accuracy Of Vector Calculation In Postoperative Rotational Adjustment Of Toric Implantable Collamer Lens

Rotation of the toric implantable collamer lens (TICL) following posterior chamber phakic intraocular lens implantation may lead to changes in refractive status, affecting postoperative visual acuity and quality. This study aims to explore a refractive correction strategy based on vector calculation for TICL rotation, providing precise and personalized treatment plans for clinical practice.

Retrospective cohort study.

 A total of 16 patients (16 eyes) with TICL rotation occurring at least 3 months after implantation were enrolled from February 2023 to December 2024 at our institution. The preoperative refractive errors ranged from -3.00DS to -14.50DS for spherical power and -2.00DC to -4.50DC for cylindrical power. Relevant clinical data were recorded, including preoperative and postoperative refractive errors, corneal topography, TICL parameters, and postoperative lens rotation angles. Vector analysis was employed to quantify the refractive changes induced by lens rotation, and TICL repositioning was performed based on the calculation results. The efficacy and safety of the adjustments were evaluated.

 Among the 16 eyes, 6 eyes were adjusted back to the originally planned axis, while 10 eyes were repositioned to a newly calculated axis. Postoperative visual acuity significantly improved and largely achieved the target visual acuity (P<0.05) following vector calculation-guided adjustments. The adjusted TICL axis showed a high correlation with preoperative and postoperative refractive errors, corneal topography, TICL parameters, and lens rotation angles.

Vector calculation can accurately quantify refractive changes caused by TICL rotation and guide the design of lens repositioning strategies. This method demonstrates good safety and efficacy in correcting refractive errors and astigmatic axis deviations, providing reliable clinical evidence for precise postoperative TICL rotation correction.