Influencing factors comparing different vault groups after phakic implantable collamer lens implantation: review and meta-analysis

Abstract Background Studies on the factors affecting vault after posterior chamber phakic Implantable Collamer Lens (ICL) have been carried out, but most of them are single-centered and subjective selections of parameters. The present study aimed to systematically analyze the factors for vault. Methods A systematic review of case series, case-control, and cohort studies derived from the articles published in PubMed, the Cochrane Library, Embase, Web of Science, CNKI, CBM, Wanfang and VIP, as well as ClinicalTrials, which were conducted to search for studies on factors of vault using four core terms: phakic intraocular lenses, vault, risk factor and observational study, from January 01, 1997, to February 20, 2023. The included studies were meta-analyzed quantitatively and described qualitatively. Subsequently, meta-regression and subgroup analysis were used. Results We identified 13 studies (1,607 subjects), and 14 factors were considered. Meta-analysis showed that anterior chamber depth (ACD), horizontal corneal white-to-white (hWTW), ICL-size, and age are dual effects of the abnormal vaults; anterior chamber volume (ACV) and lens thickness (LT) are a one-way effect; while axial length (AL), ICL- spherical equivalent (ICL-SE) and Km are insignificant. In addition, descriptive analysis of anterior chamber angle (ACA), horizontal sulcus to sulcus (hSTS), ciliary processes height (T value), crystalline lens rise (CLR), and gender showed that all factors except gender tend to have significant effects on vault. Sensitivity analysis showed stable combined results. Country and design respectively affect the heterogeneity in ACD and ICL-size at low vault, while design affects the heterogeneity in ACD at high vault. No publication bias exists. Conclusions Vault after ICL is related to multiple factors, especially anterior segmental biologic parameters, and they are weighted differently. We hope to provide a reference for the selection and adjustment of ICL.