The relationship between progression of visual field defects and retrobulbar circulation in patients with glaucoma

PURPOSE: To investigate whether lower blood flow velocities and higher resistive indices in the retrobulbar arteries are associated with progression of visual field defects in eyes with open-angle glaucoma with or without increased intraocular pressure. METHODS: Color Doppler imaging was performed in 16 eyes with progressive visual field defects in patients with normal-tension glaucoma, 15 eyes with practically stable visual field defects in patients with normal-tension glaucoma, 14 eyes with progressive visual field defects in glaucomatous patients with increased intraocular pressure, and 14 eyes with practically stable visual field defects in glaucomatous patients with increased intraocular pressure, Peak systolic velocity and end-diastolic velocity were measured, and resistive index was calculated in the central retinal artery, short posterior ciliary arteries, and the ophthalmic artery. RESULTS: Eyes with progressive visual field defects in patients with normal-tension glaucoma had statistically significantly lower blood flow velocities and higher resistive index in the central retinal artery and the short posterior ciliary arteries than did those with practically stable visual field defects, whereas, in the glaucomatous patients with increased intraocular pressure, such differences were not found. CONCLUSIONS: Eyes of patients with normal-tension glaucoma and progressive visual field defects have decreased blood flow velocities and increased resistive indices in their retrobulbar arteries, suggesting that these circulatory factors may be associated with the deterioration of visual field defects in patients with normal-tension glaucoma but may be less involved in the deterioration in glaucomatous patients with increased intraocular pressure.