Purpose: To evaluate orbital blood flow velocities in patients with pseudoexfoliation glaucoma (PXG) or primary open-angle glaucoma (POAG). Methods: Blood flow velocities in the ophthalmic, central retinal, and posterior ciliary arteries were evaluated by color Doppler imaging in 26 patients with PXG, 28 patients with POAG and 30 age-matched normal control subjects. The results were compared. Results: Compared to the control subjects, patients with PXG showed statistically significant decreases in the mean peak systolic and end-diastolic velocities and increased mean resistive indices in all vessels except for the ophthalmic artery mean peak systolic velocity (p < 0.05). Patients with POAG, when compared to the control subjects, showed statistically significant decreases in the mean end-diastolic velocities and increased mean resistive indices in all vessels measured (p < 0.05). No statistically significant differences were found in the mean blood flow parameters between POAG and PXG. Conclusion: Blood flow velocities of the retrobulbar vessels are decreased in patients with PXG. Reduced blood flow velocities may be secondary as well as contributory to exfoliative glaucomatous damage. Although there was no significant difference in the mean blood flow parameters between POAG and PXG, alterations of retrobulbar vessels might be associated with different pathogenic mechanisms of PXG. Copyright (C) 2001 S. Karger AG, Basel.