The aim of this study was to evaluate the accuracy of existing implantable collamer lens (ICL) sizing formulas, specifically the NK and KS formulas using CASIA2 and ANTERION devices, and to introduce a novel method aimed at improving the predictability of postoperative vault outcomes.

Retrospective case series.

Preoperative measurements were taken using both CASIA2 and ANTERION devices. The efficacy of the NK and KS formulas, which are integrated into CASIA2, was assessed by comparing their predicted vault values against actual postoperative measurements obtained one month after surgery. A stepwise multiple regression analysis was performed with the aim of developing a new, more accurate predictive formula for optimal ICL sizing.

When compared to the existing NK and KS formulas, the new formula developed from ANTERION measurements demonstrated superior accuracy in predicting optimal ICL size, with a mean vault of 0.535 ± 0.200 mm, compared to 0.419 ± 0.172 mm and 0.466 ± 0.103 mm for the NK and KS formulas, respectively. The regression analysis identified several significant parameters influencing the determination of optimal ICL size.

This study presents a novel formula for ICL sizing that leverages measurements from the ANTERION device, supported by a detailed multiple regression analysis. The findings suggest that this new approach significantly enhances the accuracy of ICL size prediction, potentially reducing the risk of complications associated with improper sizing.