Psychophysical mechanisms and treatment of vasospastic disorders in normal-tension glaucoma

Vasospasms are inappropriate constrictions of small vessels leading to a variety of clinical pictures depending on the location of such spasms. Although the pathophysiological mechanism is not yet well understood, we know some factors able to provoke spasm in patients with appropriate predisposition like hemorrhage, coldness, emotional stress and others. Such vasoconstrictions provoke normally relative mild symptoms like cold fingers, or pain as in variant angina and in only very rare cases, to irreversible structural damage such as myocardial infarction. There is not much known about the involvement of the eye in vasospastic disorders. Retinal migraine is a known entity but occurs quite seldom. If one looks for it, one can often find (mostly reversible) visual field damage in patients with vasospastic disorders. This might be a sign of a reversible functional damage most probably due to a decreased circulation in the optic nerve head or the surrounding choroid. In most of these patients the optic nerve head looks normal, sometimes slightly pale. In patients with the so-called normal-tension glaucoma however, the prevalence of vasospastic disorders, is very clearly increased. This leads to the hypothesis that recurrent vasospasm in the eye may, in some cases, finally lead to structural damage, presenting itself phenomenologically as normal-tension glaucoma. Therefore treatment or selected normal tension glaucoma patients with calcium-channel-blockers is helpful, as has been proven in prospective studies.