A 54 year old emmetropic woman is referred to the hospital eye service because her optometrist detected a visual field defect in the presence of normal intraocular pressure using non-contact tonometry. She is otherwise fit and well, is a non-smoker, takes no medications, and has no family history of ocular disease. Examination shows cupping of the optic discs and significant visual field loss. The applanation ocular pressures are never greater than 18 mm Hg at the clinic and during 24 hour phasing, and the clinical diagnosis is low tension—that is, normal pressure, glaucoma (NPG). Why, in the absence of elevated ocular pressure, has this woman developed glaucomatous optic neuropathy?

On further questioning, she admits to having cold hands and feet (“my husband says that my feet are always freezing when I cuddle up to him at night”), and also has a history of migraine headaches since her teenage years. What is the relevance of these two vasospastic conditions—Raynaud-like peripheral circulation and migraine—to the case presented above.

Vasospasm is the term used to describe an abnormal vascular responsiveness to common everyday stimuli such as cold, stress, or nicotine.1 This process may reflect an …