<h4>Purpose</h4>We explored the role of oxytocin in glaucoma by measuring the blood levels of oxytocin in glaucoma patients, comparing them to normal control subjects, and examining its association with clinical parameters.<h4>Study design</h4>Retrospective cross-sectional study.<h4>Material and methods</h4>After obtaining informed consent from 181 glaucoma patients and 44 age-matched control participants, we collected blood samples in ethylenediaminetetraacetic acid (EDTA) tubes and centrifuged them at 2000 g for 25 minutes at 4 °C. This evidence concerns the gene OXT and glaucoma.