Corneal Cross-Linking in Keratoconus: A Scoping Review of Clinical Evidence and Public Health Implications

Objective. To map and synthesize recent evidence on the efficacy, safety, adherence, and cost-effectiveness of corneal cross-linking (CXL) for keratoconus, with emphasis on its public health implications. Methods. A scoping review was conducted following Arksey and O’Malley’s framework, complemented by the recommendations of Levac, Colquhoun, and O’Brien, and in accordance with the PRISMA-ScR guideline. Studies published between 2021 and 2024 were retrieved from Scopus, PubMed, and Web of Science. Two independent reviewers performed study selection and data extraction. Quantitative data were analyzed through descriptive statistics, while qualitative findings were synthesized using specialized software. Results. From 596 initial records, 43 studies were included. Retrospective (46.51%) and prospective (37.21%) designs predominated, mainly focused on adult populations. CXL stabilized keratoconus progression in 90–95% of cases. The standard protocol remained the reference, while the accelerated protocol showed comparable efficacy with practical advantages, particularly in pediatric populations. Transepithelial and iontophoresis-assisted modalities exhibited acceptable safety but heterogeneous efficacy. Adapted protocols for ultrathin corneas expanded clinical indications without compromising endothelial safety. Conclusions. Available evidence supports CXL as an effective and cost-effective intervention to halt keratoconus progression, reduce the need for corneal transplantation, and preserve visual function. Its applicability across diverse clinical settings underscores its value as a public health priority. However, gaps remain regarding protocol standardization and context-specific economic evaluations.