Background:Although the main pathological changes have been defined in the pulmonary vascular bed in Chronic Obstructive Pulmonary Disease (COPD), we postulated that the retrobulbar hemodynamics might also be changed in those patients. Aim of the work: to evaluate the retrobulbar arterial blood flow changes in COPD patients by color Doppler ultrasonography.Methods: Fifteen stage I COPD, 16 stage II COPD, 14 stage III COPD patients and 20 healthy control subjects were included in this study. Arterial blood gases and spirometry were done for COPD patients. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) were measured in the ophthalmic artery (OA), central retinal artery (CRA), posterior ciliary arteries (PCAs), usingcolor Doppler ultrasonography. Measurements were performed in only one randomly chosen eye of each participant. Results: PSVs and EDVs measurements of all arteries did not differ significantly between controls and group I (p > 0.05). PSVs in the CRA and PCA were significantly higher in group II compared to the control group (p < 0.05). RI values of CRA and PCA in groups I, II, III were significantly higher compared to control subjects (p < 0.05). RI values of OA in group II were significantly higher than in those of controls (p < 0.01). Conclusions:Patients with COPD have impaired flow in the central retinal and posterior ciliary arteries, most probably due to increased resistance in the retinal vascular bed to blood flow.