International reporting guidelines for tear fluid research: A Delphi consensus.

Purpose: Tear fluid is a valuable biomarker source for diagnostics, monitoring, and screening thanks to its minimally invasive, inexpensive, and rapid collection. However, the lack of standardized reporting has hindered reproducibility in the field. To address these challenges, this study aimed to establish international consensus-based reporting guidelines tailored to tear fluid research.

Methods: Using the Delphi methodology, the Tear Research Network engaged 74 international professionals to evaluate 35 proposed reporting statements. These statements covered essential aspects of tear fluid research, including terminology, collection, storage, pre-analytical processing, analysis, and data normalization. Professionals ranked their agreement on the need to include each of the statements based on a 5-point Likert scale (very unimportant - very important). Consensus was defined as ≥70 % agreement, and all ratings were collected and analyzed anonymously.

Results: Consensus was achieved for 34 of the 35 proposed statements in the first Delphi round, reflecting a high level of agreement among professionals, with 26 of these statements reaching strong consensus at agreement levels of 90% or higher. The resulting guidelines provide detailed recommendations to standardize reporting, improve transparency, and enhance reproducibility in tear fluid studies.

Conclusions: The TEAR-reporting guidelines (TEAR-RG) represent a significant step toward standardizing research practices in tear fluid studies. By addressing key methodological and reporting issues, these guidelines aim to improve the reproducibility and transparency of research in this rapidly evolving field. This work underscores the importance of standardized frameworks for advancing biomarker discovery and clinical applications in tear fluid research.