A prospective evaluation of indirect methods for detecting carotid atherosclerosis.

The statistical efficacy of three indirect techniques for noninvasive diagnosis of carotid artery disease was assessed in a prospective, blind study of 103 persons. Oculoplethysmography-carotid phonoangiography, periorbital Doppler examination and supraorbital photoplethysmography were acceptably sensitive only to carotid artery occlusions and preocclusive carotid artery stenoses exceeding a 75 per cent diameter reduction. Less pronounced lesions could not be reliably detected by any of the techniques used either singly or in combination. Supraorbital photoplethysmography proved inferior to the other methods because of its poor specificity rate.