Background: Previous studies identified myopia as a risk factor for primary open-angle glaucoma (POAG). However, recent studies have shown different results, and the definitive relationship between myopia and POAG remains controversial. Objectives: The aim of this study was to investigate the relationship between myopia and POAG. Methods: Published articles were searched from PubMed, Embase, and Scopus databases between 1970 and 2020. A pooled analysis of the odds ratios (ORs) was performed using a random-effects model. Results: Data on the association between myopia and POAG were obtained from 16 cross-sectional studies, and the pooled OR was 2.26 (95% confidence interval [CI], 1.77-2.89, p < 0.001) in random-effects model (I-2 = 86%; p < 0.01). For the relationship of myopia and POAG progression, data from 7 longitudinal cohort studies were included, and the pooled OR was 0.85 (95% CI, 0.73-0.99, p = 0.042) in the random-effects model (I-2 = 88%; p < 0.01). Conclusion: Our findings demonstrated that myopia may be a risk factor associated with POAG and a possible protective factor for POAG progression. It may be due to myopia with the presence of a lamina cribrosa defect, slowing down the visual field loss and also POAG progression. Further research for underlying mechanisms is still needed. (C) 2021 The Author(s).Published by S. Karger AG, Bas