Effects of White-to-White Diameter and Anterior Chamber Depth on Implantable Collamer Lens Vault and Visual Outcome

PURPOSE: To investigate the effects of anterior chamber depth (ACD) and white-to-white (WTW) diameter on vault in eyes with implantable collamer lenses (ICL V4, STAAR Surgical AG) and to evaluate the effect of vault on visual outcomes and other biometric changes. METHODS: Twenty-eight eyes of 16 patients who underwent ICL implantation were retrospectively reviewed. Patients were divided into two groups (A1, A2) according to preoperative ACD (> or = 3.3 mm and < 3.3 mm, respectively), two groups (B1, B2) based on WTW diameter (> or = 11.55 mm and < 11.55 mm, respectively), and two groups (C1, C2) according to the difference of ICL diameter and sulcus length (> or = 0.25 mm and < 0.25 mm, respectively). Vault, endothelial cell density, and visual performance were compared between each set of groups. Correlations of vault with WTW diameter, ACD, and diametric difference of the ICL from the sulcus were analyzed. RESULTS: The high ACD and WTW groups showed significantly higher vaults (0.59 +/- 0.32 mm and 0.57 +/- 0.36 mm, respectively) than the low ACD and WTW groups (0.26 +/- 0.17 mm and 0.25 +/- 0.14 mm, respectively; P = .01 and .01), whereas the differences of diameter between the sulcus and ICL were not related to significant vault differences. The WTW diameter wascorrelated more closely to the vault than the ACD or sulcus diameter (r = 0.70, P < .001), whereas the vault difference did not affect visual quality or endothelial cell density. CONCLUSIONS: A high WTW diameter or ACD is likely to render a high vault, regardless of any difference in the ICL and sulcus diameters.