Retinal circulation in primary open-angle glaucoma tested by videodensitometric image analysis.

To investigate the retinal circulation in primary open-angle glaucoma (POAG), we used videodensitometric image analysis of fluorescein angiography to calculate the build-up time, the time constant of the washout rate, and the mean circulation time (MCT) in both the retinal artery and vein. We found the MCT in the POAG group (23 eyes of 20 patients) was significantly longer than in the normal group (3.7 +/- 2.0 sec and 2.8 +/- 1.7 sec, respectively; P less than .05). It correlated significantly with the vertical cup-to-disc ratio (r = .32; P less than .01), the outflow facility (r = -.35, P less than .005), and the glaucomatous visual-field loss. There was no correlation between MCT and intraocular pressure tested at the same time (r = .09, not significant). Therefore, treatment to decrease the intraocular pressure may not be associated directly with improved retinal circulation.