Analysis of pre-operative factors affecting range of optimal vaulting after implantation of 12.6-mm V4c implantable collamer lens in myopic eyes

Background: To evaluate clinical factors affecting postoperative vaulting in eyes that had achieved optimal vaulting within the range of 250-750 μm following implantation of 12.6-mm V4c implantable collamer lenses (ICL). Methods: A total of 236 eyes of 236 patients that had achieved optimal vaulting following implantation of a 12.6-mm V4c ICL were retrospectively analyzed. Associations between postoperative vaulting and age, preoperative anterior chamber depth (ACD), preoperative axial length (AL), preoperative white-to-white diameter, preoperative pupil size, preoperative sulcus-to-sulcus diameter, and preoperative manifest refraction spherical equivalent were investigated using simple regression, stepwise multiple regression, and multinomial logistic regression analyses. Results: Mean central vaulting at the 6-month follow-up was 519.0 ± 112.8 μm. Variables relevant to postoperative vaulting were, in order of influence, preoperative ACD (β = 0.305, p < 0.001), preoperative pupil size (β = 0.218, p < 0.001), and preoperative AL (β = 0.171, p = 0.006). Low preoperative pupil size was associated with low optimal vaulting (250 to 450 μm), relative to that observed in the mid optimal vaulting group (451 to 550 μm) (odds ratio = 0.532, P = 0.021). Increasing preoperative ACD was associated with high optimal vaulting (551 and 750 μm), relative to that observed the mid optimal vaulting group (odds ratio = 6.340, P = 0.034). Conclusions: Myopic eyes with greater preoperative ACD, larger pupil size, and longer AL are predisposed to higher postoperative vaulting following 12.6-mm V4c ICL implantation. Therefore, the extremes of these parameters should be considered when choosing V4c ICL size.