Variations in ocular hemodynamics in patients with early and late glaucoma

Abstract

ABSTRACT.Purpose: To determine the retrobulbar hemodynamics in glaucoma patients with different degrees of optic nerve damage. Methods: Color Doppler imaging was performed in 52 patients with controlled primary open angle glaucoma (POAG) and in 25 control subjects. Glaucomatous eyes were divided into early and late groups based on the perimetry findings. Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index of the central retinal artery (CRA) and posterior ciliary arteries (PCA) were evaluated. Results: Early glaucoma showed significantly decreased PSV in nasal PCA when compared with the normal. Late glaucoma showed significantly decreased PSV and EDV in the CRA and nasal PCA, and significantly decreased PSV in temporal PCA as compared with the control and early glaucoma. The resistive index of the CRA also increased significantly in late glaucoma. Conclusion: Eyes with advanced glaucomatous optic neuropathy were associated with more marked alterations in retrobulbar circulation than eyes with less nerve damage.

Topical phenylephrine decreases blood velocity in the optic nerve head and increases resistive index in the retinal arteries

“…The circulation in the optic nerve head (ONH), posterior retina, or retrobulbar vessels is likely to be altered in glaucoma patients, 1-10 especially those with worse or deteriorating visual field damage, 5,7,[10][11][12][13] which suggests that the impaired ocular circulation is one of the factors responsible for the development of glaucoma. There have been several reports that demonstrated cupping in the ONH followed decreased ocular perfusion without a high intraocular pressure (IOP) in animal experiments.…”

Performance of colour Doppler imaging discriminating normal tension glaucoma from healthy eyes

“…A reduction in flow velocities and an increase in the calculated resistive indices (RI) of all these retrobulbar vessels have been reported in NTG compared to healthy controls in different studies. [13][14][15][16][17][18][19] The blood flow velocities of retrobulbar vessels have been correlated to functional defects in glaucoma 20,21 and are associated with interocular differences in asymmetric visual field defects. 22 In addition, retrobulbar blood flow velocities are linked to perfusion deficits of the optic nerve head 13 and retina 23 in glaucoma.…”

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

“…8,12 Some authors consider the finding of a correlation between the progression rate of visual field damage and baseline retrobulbar hemodynamics to be suggestive of a primary alteration in the retrobulbar blood flow in progressive glaucoma. 1,2,4,25,26 While some authors have claimed that vasospasm distal to the OA might compromise blood flow and initiate or potentiate pathologic changes in the optic nerve head, others thought that repeated transient low perfusion without any organic vascular narrowing might cause the optic nerve damage. 14,12 Studies to correlate posture and IOP changes of normal subjects and patients with glaucoma showed a deficient autoregulation of the CRA and PCA, but not of the OA, in NTG.…”

“…It have been pointed out that there is a correlation between retrobulbar hemodynamic alteration and the progression rate of glaucoma. 1,2,9,12,25,26 Furthermore, aging has been reported to cause an increase in scleral rigidity and a decrease in Values are means ± SD, with the range in parentheses. There were 41 patients with normal -tension glaucoma and 30 healthy control subjects.…”