Duplex sonography of retro-orbital and carotid arteries in patients with normal-tension glaucoma

Abstract

To evaluate retrobulbar and carotid arterial hemodynamics in patients with normal-tension glaucoma using Doppler sonography. Duplex sonography was performed in 41 patients with normal-tension glaucoma and 30 control subjects to evaluate resistance indices (RIs) in retro-orbital and carotid arteries. Mean values were compared using the independent t-test. The ratios of the RI in retro-orbital to RIs in the carotid arteries (CCA and ICA) and interocular and intercarotid differences in RI (DeltaRI) were also calculated. Is in the central retinal (CRA) and temporal and nasal posterior ciliary arteries (TPCA and NPCA) were statistically significantly greater in glaucomatous eyes (p < 0.001). Plaque formation in carotid arteries without significant stenosis was noted in 12% of patients and 10% of control subjects. Ratios of RI of CRA or TPCA or NPCA to that of CCA and the ratios of RI of CRA or NPCA to that of ophthalmic arteries (OA) were significantly greater in glaucomatous eyes. We also found that ratios of the RI of CRA or TPCA or NPCA to that of ICA and the ratio of the RI of OA to CCA were nearly equal to 1 in both patients and control subjects. We found no significant difference between interocular and intercarotid DeltaRIs in patients and control subjects. In patients with symmetric normal-tension glaucoma, duplex sonography showed an elevated RI in CRA and PCA. The Doppler evaluation of carotid arteries was useful.