Advances in Intracorneal Ring Segment (ICRS) Implantation for Keratoconus: A Comprehensive Literature Review, Clinical Insights, and Future Prospects.

Keratoconus is a progressive corneal disorder that causes thinning and irregular astigmatism, often leading to significant visual impairment. In the advanced stages, surgical interventions are necessary to restore corneal shape, improve vision, and enhance contact lens tolerance. Intracorneal ring segments (ICRSs) have emerged as a well-established, minimally invasive option that not only improves vision but also has the potential to delay or prevent the need for corneal transplantation in advanced cases. Recent advancements in the ICRS implantation techniques, patient selection, and femtosecond laser technology have significantly improved the precision and safety of these procedures, reducing complications. The ability to customize the ring parameters-such as thickness, arc length, and positioning-enables a more individualized approach, particularly for patients with irregular astigmatism. Artificial intelligence (AI) is also emerging as a promising tool for optimizing ICRS planning and improving patient outcomes. Although still in the early stages, AI algorithms may refine the treatment strategies by analyzing large datasets, improving the patient selection, and predicting long-term outcomes. Corneal Allogenic Intrastromal Ring Segments (CAIRSs) offer a novel alternative to synthetic ICRSs, with advantages like improved biocompatibility and reduced extrusion risk. However, CAIRSs remain an evolving technique that requires further refinement and long-term evaluation to determine the tissue integration, the durability of the refractive outcomes, and the potential for late-onset complications. In conclusion, ICRSs continue to be a safe and effective option for managing advanced keratoconus. Ongoing refinement of the surgical approaches-combined with advancements such as femtosecond laser technology and the integration of AI-will ensure that both ICRSs and CAIRSs remain key components in the therapeutic arsenal for keratoconus, offering sustained visual improvements and the potential to delay or avoid corneal transplantation.