[Disordered peripapillary microcirculation in glaucoma patients]

To study the haemodynamics of the peripapillary choroid, perfusion pressure videoangiography (PVA) was performed in six healthy subjects and in seven patients with primary open-angle glaucoma (poag). In healthy subjects the peripapillary part of the choroid starts filling at distinctly lower ocular perfusion pressures than other parts of the choroid. The mean difference in perfusion pressure between peripapillary and perimacular filling was 13.6 mmHg in the six healthy subjects. A different filling pattern of the choroid was found in the seven glaucoma patients. The mean difference in perfusion pressure between the beginning of peripapillary and the beginning of perimacular perfusion of the choroid was found to be as small as 1.9 mmHg. That the filling of the peripapillary choroid observed by PVA in healthy subjects is found to start at lower perfusion pressures than in the other parts is explained by autoregulative dilatation of the peripapillary choroidal arterioles resulting from artificially raised intraocular pressure during the PVA examination. In the poag patients the peripapillary choroidal arterioles were dilated either insufficiently or not at all. The following conclusions are drawn: (1) The peripapillary choroid of healthy persons shows effective autoregulation securing the blood supply to the prelaminar part of the optic nerve. (2) In poag the peripapillary choroid has lost the capability of effective autoregulation.