Diagnostic accuracy of ocular pneumoplethysmography attachment for pulse volume recorder

The ocular pneumoplethysmography (OPG) attachment for the Life Sciences Pulse Volume Recorder (OPG-LS) is a widely distributed instrument, but no results have been published on its accuracy in diagnosing carotid artery lesions. One hundred twelve patients were studied with the OPG-LS using lateralizing criteria and a curve of ophthalmic artery systolic pressure (OAP) to brachial systolic pressure (BP) for normal carotid arteries, which served as a discriminant between normal and stenotic vessels. Two hundred nineteen carotid arteries were visualized on arteriography and percentage of diameter stenosis was measured. Lateralizing criteria by themselves gave poor diagnostic accuracy, but when combined with OAP-BP data, positive diagnosis was made for lesions having greater than 60% diameter stenosis in 89.6% of patients and 80.8% of arteries. False-positive results for 0% to 30% diameter stenotic lesions occurred in 11.1% of arteries and in 13.6% of patients.