Assessment of orbital hemodynamic changes in primary open angle glaucoma by color Doppler imaging.

PURPOSE: To assess changes in orbital vessels by Color Doppler Imaging (CDI) in patients with Primary Open Angle Glaucoma (POAG). METHODS: This cross-sectional study included 120 subjects - 60 patients with POAG and 60 controls, all of whom underwent full ophthalmological examinations and orbital CDI. The Ophthalmic Artery (OA), Central Retinal Artery (CRA) and Ciliary Arteries (CA) were identified, and for each of them, we measured Peak Systolic Velocity (PSV), End Diastolic velocity (EDV) and Resistivity Index (RI). RESULTS: The PSV of the OA and CRA were significantly lower in patients with POAG compared to normal controls (P<0.0001, < 0.009 respectively). The EDV in the OA, CRA and CA were significantly lower than in normal controls (P<0.0001). The RI of the OA, CRA and CA were significantly higher in patients with POAG compared to controls (P<0.0001). The EDV of the OA showed significant negative correlation with duration of glaucoma (r=-0.37, P<0.042). The EDV of the CA showed significant negative correlation with intraocular pressure (IOP) (r=-0.86 and P value 0.0001). The PSV and EDV of the CRA showed significant negative correlation with IOP (r=-0.45, r=-0.73, P values 0.011, and 0.0001 respectively), and the RI of the CRA showed significant positive correlation with IOP (r=0.42 and P value 0.021). CONCLUSION: CDI is a feasible, noninvasive, safe tool for the assessment of hemodynamic changes in the orbital arteries of POAG patients. The orbital arteries showed significantly lower flow velocities and increased resistivity indices in patients with POAG compared to the control group, and these changes were correlated with glaucoma duration and IOP.