Purpose: To identify the differences in risk factors and visual field (VF) changes between juvenile primary open-angle glaucoma (JOAG) and late-onset chronic open-angle glaucoma (COAG). Methods: The demographic and presenting clinical data of 27 JOAG and 30 COAG patients were retrospectively reviewed. Comparisons between the two groups were performed using Mann-Whitney U test, Wilcoxon signed-rank test, and Fisher’s exact test. Results: A family history of glaucoma (37%) and a history of steroid usage (14.8%) were identified in JOAG patients only. The JOAG patients had a longer axial length (p < 0.001) and more often a myopic refractive state (p < 0.001) than the COAG patients. Patients with COAG showed a deeper (p = 0.016) and a more extensive (p = 0.008) defect in the superior than in the inferior hemifield, as well as a deeper (p = 0.016) and a more extensive (p = 0.001) defect in the superior than in the inferior arcuate area, while JOAG patients showed symmetric VF defects between the superior and inferior hemifields. Purely diffuse VF depression is more common in JOAG than in COAG patients (p = 0.03). Conclusions: JOAG patients demonstrated more axial myopic changes than patients with COAG as well as a pattern of superior-inferior symmetric VF defects. Axial myopia may play a critical role in the pathogenesis of JOAG.