Research on a New Model for Predicting Vault After Implantable Collamer Lens (ICL) Based on Structural Parameters of...

To fit a new prediction model of the implantable collamer lens (ICL) vault including the parameters of the posterior chamber structure and to validate the accuracy of the new model.

Seventy patients (92 eyes) undergoing ICL implantation were enrolled in the prediction model group. Spearman's rank correlation was used for univariate analysis to assess the relationship between postoperative vault and preoperative ocular parameters. A vault prediction model was developed using multiple linear regression. An independent validation cohort comprised 140 patients (204 eyes) who received ICL implantation. All patients completed preoperative ocular examinations. Postoperative vault was measured at 1 month. We calculated the proportion of eyes with optimal vault (250-1000 μm). Agreement between predicted and actual vault was assessed using (1) intraclass correlation coefficient (ICC); (2) Bland-Altman analysis (95% limits of agreement, LoA); and (3) 95% confidence intervals for mean differences.

The mean age of the sample included in the prediction model was 28.18 ± 7.07 years. Vault was positively correlated with spherical equivalent (SE), white-to-white (WTW) horizontal corneal diameter, anterior chamber depth (ACD), anterior chamber volume (ACV), horizontal sulcus-to-sulcus (hSTS) diameter, pupil diameter, and maximum ciliary body thickness (CBTmax) and negatively correlated with age, intraocular pressure (IOP), crystalline lens rise (CLR), and trabecular-ciliary process angle (TCA). The vault prediction model (adjusted R ² = 0.54) was as follows: vault (μm) = -1711.7-166.8 × ICL size + 378.6 × WTW horizontal corneal diameter + 506.8 × ACD - 11.8 × TCA. In the validation cohort, the prediction model demonstrated clinical utility with 88.2% of outcomes within the ideal vault range (250-1000 μm) and 95.1% of errors within ±500 μm. The correlation coefficient between the predicted vault and the actual vault is 0.51 (p < 0.01). The bias between the predicted and actual vault is 203.20 μm, with a 95% LoA of (-175.30-581.70) μm and a standard deviation (SD) of 193.10 μm; the ICC between the predicted vault and the actual vault is 0.51 (95% CI: 0.40, 0.60).

The vault prediction model, incorporating the posterior chamber structural parameter TCA, demonstrated favorable predictive performance in an independent validation cohort. It may serve as a useful supplementary tool for ICL size selection.