Implantable collamer lens surgery for high myopia: safety boundaries, vault management, and patient selection

Posterior chamber implantable collamer lens (ICL) implantation provides additive refractive correction for selected phakic patients, especially those with high myopia and limited corneal laser options. This narrative Mini Review synthesizes literature published mainly from January 2021 through May 2026 to connect patient selection with measurable safety boundaries, separate lens power and size planning, dynamic vault assessment, and long-term surveillance. It also discusses hyperopic ICLs, non-EVO lenses, alternative phakic IOL platforms such as IPCL, and emerging artificial intelligence. True anterior chamber depth, age-appropriate endothelial reserve, open angles, crystalline lens status, and refractive stability define eligibility. Central vault is interpreted using pragmatic numerical categories alongside angle, pressure, and lens findings; no single vault threshold guarantees safety or mandates exchange. Refractive and vault prediction models have different inputs and outcomes, and favorable average accuracy does not establish performance in extreme or underrepresented anatomy. Modern central-port ICLs show good outcomes in appropriately selected myopic eyes, while evidence for hyperopic and alternative platforms is smaller and not interchangeable. The proposed clinical framework represents expert synthesis rather than a validated decision rule. Future priorities include externally validated multimodal prediction and prospective lifelong safety monitoring.