Perfusion of the optic nerve head and visual field damage in glaucomatous patients

To examine the relation between perfusion of the optic nerve head and visual field defects in glaucomatous patients.

A study was performed on 94 patients affected with primary open-angle glaucoma. The optic nerve head blood flow was measured by means of a scanning laser Doppler flowmeter (Heidelberg Retina Flowmeter). Blood volume, flow and velocity were analysed in two areas of the rim and in one area of the lamina cribrosa. The visual field was tested with the 30-2 full threshold white-on-white program and mean deviation (MD) and corrected pattern standard deviation (CPSD) were considered as parameters of visual field defects.

The interindividual analysis showed that the vascular parameters of the neuroretinal rim circulation were not significantly correlated with visual field parameters. The blood volume, flow and velocity of lamina cribrosa correlated significantly with both MD (R=0.519, R=0.549 and R=0.531, respectively; P<0.001) and CPSD (R=-0.496, R=-0.363 and R=-0.363, respectively; P<0.001). The intraindividual correlations (right-left differences of parameters) showed that the side differences of MD and CPSD correlated significantly with the side differences of blood volume (R=0.511 and R=-0.477, respectively), flow (R=0.554 and R=-0.390, respectively) and velocity (R=0.541 and R=-0.372, respectively) in lamina cribrosa.

These findings suggest that in glaucoma patients the perfusion parameters of lamina cribrosa are significantly correlated with visual field defects.