Efficacy, Predictability, and Safety of Phakic Implantable Collamer Lenses V4c and V5: A Systematic Review and Meta-analysis

Purpose: To evaluate the efficacy, predictability, safety, and complication profile associated with the latest posterior chamber phakic Implantable Collamer Lenses (ICLs) featuring a central port (models V4c and V5; STAAR Surgical). Methods: This PROSPERO-registered systematic review and single-arm meta-analysis included prospective ICL V4c or V5 implantation studies in adults without ocular comorbidities. Databases searched included PubMed, Embase, and the Cochrane Library through May 2025. Primary outcomes were efficacy, predictability, and safety; secondary outcomes included intraocular pressure, endothelial cell density, and complications. Results: Twenty-seven studies comprising 2,204 myopic eyes were included, with a mean follow-up of 13.84 months. Final uncorrected distance visual acuity (UDVA) averaged 0.057 ± 0.022 logarithm of the minimum angle of resolution (logMAR), with 80.23% achieving 20/20 or better. The mean efficacy index was 1.103 ± 0.019. Predictability was high: 87.45% of eyes were within ±0.50 diopters (D) of the intended refraction. The mean corrected distance visual acuity (CDVA) was 0.014 ± 0.020 logMAR, and the safety index averaged 1.185 ± 0.021. Intraocular pressure remained stable postoperatively (15.98 ± 0.531 mm Hg), and endothelial cell density showed a statistically significant but clinically acceptable decrease. Complications were infrequent, with no vision-threatening events reported. Conclusions: This meta-analysis of ICLs with a central port (V4c and V5) demonstrates high levels of efficacy, refractive predictability, and safety for correcting moderate to high myopia. The incidence of serious adverse events was low, and results were consistent across a broad range of prospective studies. Continued long-term follow-up and geographically diverse populations are warranted to further validate these findings.