AIM: To develop a critical pathway for primary open angle glaucoma (POAG) diagnosis intended to be efficient, to unify criteria, reduce resource use and minimize costs to the health system. METHODS: We performed a systematic search on PubMed, Cochrane, Embase and ClinicalTrials.org databases and classified the quality of evidence from level I through III. RESULTS: A critical pathway was designed by setting a key-decision step by step model on the basis of the best current evidence. CONCLUSION: A critical pathway, evidence-based guideline, may be a useful tool intended to reduce costs while maintaining or even improving the quality of care for diagnosing a highly prevalent pathology such as open angle glaucoma.