Systematic analysis of outcome indicators in traditional Chinese medicine clinical research for dry eye: A review

This narrative review systematically analyzes outcome indicators in clinical research on traditional Chinese medicine (TCM) interventions for dry eye, aiming to analyze current methodological patterns and establish foundations for core outcome set development. Through comprehensive searches across Chinese (China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, Wanfang) and English databases (PubMed, Cochrane Library, Embase), 863 clinical studies were identified and analyzed for outcome indicator usage. Forty-six distinct outcome indicators were documented, cumulatively appearing 3885 times across 6 categories. The most frequently employed metrics were tear film break-up time (772 times), Schirmer test (753 times), and corneal fluorescein staining (559 times). Significant methodological concerns emerged, including marginalization of TCM-specific indicators, nonstandardized outcome reporting, substantial heterogeneity in indicator combinations lacking theoretical justification, poor clinical applicability, and absence of economic evaluations. The findings underscore the urgent need to develop a standardized core outcome set for TCM dry eye research to enhance methodological rigor, strengthen evidence synthesis, and optimize the integration of TCM’s therapeutic advantages in dry eye management.