Vault-correlated efficacy and safety of Implantable Collamer Lens V4c implantation for myopia in patients with shallow anterior chamber depth

Introduction: To evaluate efficacy and safety outcomes after implantation of the Visian Implantable Collamer Lens (ICL V4c) in myopia patients with shallow anterior chamber depth (ACD).Methods: This retrospective study followed 163 eyes of 94 patients for at least 24 months. Uncorrected distance visual acuity, corrected distance visual acuity, intraocular pressure (IOP), manifest refraction, vault, endothelial cell density (ECD), anterior chamber angle (ACA), anterior chamber volume (ACV) and the distance from the corneal endothelium to the central ICL (C-ICL) were measured during follow-ups. Spearman's correlation and logistic regression were used to identify variables correlated with changes in ECD and potential risk factors for ineffective outcomes, respectively.Results: All surgeries were performed safely. High IOP of 9 eyes and anterior capsular opacity of 5 eyes were observed. The last follow-up ACA had a significant difference between the high and normal IOP groups (P = 0.0003). The mean ECD and vault was 2855.76 +/- 270.82 cells/mm2 and 388.01 +/- 135.28 mu m at the last follow-up, respectively. The vault and C-ICL were significantly associated with Delta ECD (all P < 0.01). Furthermore, the vault was most responsible for the ECD loss. Twenty-two eyes had unsatisfactory postoperative UDVA, and the low vault at the last follow-up was a significant risk factor for this ineffective outcome (P < 0.001, OR = 14.739).Conclusions: ICL V4c implantation in patients with shallow ACD achieved stable visual outcomes. The vault is related to postoperative visual acuity and ECD loss, which needs to be paid attention during follow-up.