Correlation of optic disc morphology and ocular perfusion parameters in patients with primary open angle glaucoma

Abstract Purpose Little information is available about the relationship between glaucomatous visual field defects and reduced blood flow in the optic nerve head. It is still not clear, if impaired circulation is a causative factor in the disease process, or if it is secondary as a result of loss of axons in the optic nerve head. In the present study vascular parameters were correlated against structural damage of the optic nerve head and functional damage. Methods 103 patients with primary open angle glaucoma, documented visual field defects and optic disc morphology changes were examined. Blood flow parameters were assessed using Laser Doppler Flowmetry, Laser Doppler Velocimetry, and the Retinal Vessel Analyzer. To evaluate the morphology of the optic nerve head, a fundus photograph was taken. For determination of the degree of visual field damage, automated perimetry was performed. Results The degree of optic nerve head damage was significantly correlated with the intensity of visual field loss. Decrease in retinal vessel diameter was only slightly correlated with the degree of glaucomatous optic neuropathy and visual field defect. Reduced optic nerve head blood flow was, however, strongly correlated with the degree of visual field loss and morphological optic disc damage. Conclusion The data of the current experiment indicates that blood flow in the optic nerve head is strongly associated with the degree of visual field damage, whereas retinal vessel diameters show only little association with the degree of visual field damage.