Methodological quality evaluation of animal experiments on traditional Chinese medicine formulas for glaucoma: A systematic review

•Traditional Chinese medicine helps alleviate glaucoma.•The design, performance, and report of animal studies affect their results.•This study evaluated the quality of experiments on traditional Chinese medicine for glaucoma.•Methodological defects focus on the bias of selectivity, implementation, and measurement.•Defects in reporting mainly involve randomization, blinding, ethical statements, and animal care. This review aimed to evaluate the methodology and reporting quality of preclinical studies on traditional Chinese medicine (TCM) intervention for glaucoma, and explore areas for improvement. Eight Chinese and English databases were searched for animal experiment articles on TCM formulas for glaucoma. The risk of bias was evaluated using the SYRCLE's tool, the reporting quality using the ARRIVE 2.0 guidelines and the GSPC checklist. Seventy-two articles met the inclusion/exclusion criteria for full-text review. According to the SYRCLE's tool, 7 (70%) of the 10 items had a low-risk rate of less than 50%, high-risk items were focused on selectivity bias, implementation bias, and measurement bias. Results of the ARRIVE 2.0 guidelines showed that 20 (53%) of the 38 sub-items had a high-agreement rate of less than 50%. Using the GSPC checklist, it was determined that 10 (53%) of the 19 sub-items had high-agreement rates of less than 50%. Randomization, blinding, ethical statements, housing and husbandry, animal care and monitoring, and protocol registration were low-agreement rate aspects of study reporting. The methodology and reporting quality of animal studies on TCM formulas for glaucoma is generally low. It is advised to further refer to the SYRCLE's tool and reporting guidelines, to enhance the design, performance, and reporting of animal experiments to ensure the reproducibility and reliability of results.