Estimating Implantable Collamer Lens Vault From Scheimpflug-Derived Postoperative Anterior Chamber Volume Change in Chinese Eyes.

PURPOSE: To compensate for Pentacam's (Oculus Optikgeräte GmbH) flaw in Implantable Collamer Lens (ICL; STAAR Surgical) vault assessment, which is the difficulty to clearly detect the ICL itself, for the improvement of Pentacam's performance in the follow-up after ICL implantation.

METHODS

One hundred fourteen eyes that had ICL implantation at Beijing Fenglian Eyecare Beau Care Clinic were pre-screened from January to December 2024 and were randomly divided into the formula establishment group (76 eyes) and the formula validation group (38 eyes). A regression formula was worked out with the perioperative variables measured by Pentacam to best correlate with postoperative ICL vault measured by anterior segment optical coherence tomography (AS-OCT) using Pearson correlations and multiple linear regressions in the formula establishment group, and it was then tested in the validation group.

RESULTS

ICL vault showed significant positive linear correlations with anterior chamber volume change (ΔACV) (r = 0.845, P < .001), anterior chamber depth (r = 0.441, P < .001), and white-to-white distance (r = 0.342, P < .01). However, there was no linear correlation between ICL vault and ICL size/direction/anterior chamber angle (P > .05). The estimation formula was: ICL vault (μm) = 1,710.94 - 157.81 × ICL size (mm) +13.20 × ΔACV (μL). The validation results showed that the mean absolute error, median absolute error, and root mean square error were 82.27, 77.54, and 99.31 μm, respectively.

CONCLUSIONS

This study established the ICL vault estimation formula based on ΔACV measured by Pentacam to best correlate with vault measured by AS-OCT. It compensates for Pentacam's flaw in ICL vault assessment, which is the difficulty to clearly detect the ICL itself, and is especially valuable when AS-OCT is unavailable.