Both intraocular pressure (IOP) and vascular factors appear to play an important role in the pathogenesis of glaucomatous optic neuropathy (GON). Arteriosclerosis and its risk factors are of minor importance, whereas vasospastic syndrome clearly is associated with GON. A vascular endotheliopathy seems to be involved in the diathetic hyperresponsiveness to stimuli, such as coldness or emotional stress. This in turn leads to a compromised autoregulation, and thereby renders the eye more sensitive to IOP or to a decrease in blood pressure. A variation in ocular perfusion may lead to an increase in free oxygen radicals. This may finally lead to apoptosis.