Evaluation of extracranial cerebrovascular disease in the hypertensive patient with ocular pneumoplethysmography at 500 mm Hg.

OPG-300 is a reliable noninvasive method of detecting hemodynamically significant stenoses of the internal carotid circulation. An important limitation of the method is that patients with systemic blood pressure greater than 160 mm Hg cannot be studied; in our laboratory this represented 55 percent of the patients referred for testing. The addition of the 500 mm Hg vacuum modification now allows us to reliably test 95 percent of patients referred to our laboratory for evaluation of the extracranial cerebrovascular circulation.