The complementary value of Doppler-ultrasonography and ocular pneumoplethysmography according to Gee (OPG-Gee) in carotid obstructions

The results of the combination of CW-Doppler ultrasonography and OPG-Gee are described in 68 patients. The Doppler examination had a sensitivity of 92% and a specificity of 89%, the percentages for the OPG-Gee were 69 en 79. The combination of the Doppler examination with the OPG-Gee improves our positive predictive value from 83 to 94%, the negative predictive value from 95 to 98% in concordant results. OPG-Gee fails especially in low-graded (50-74%) stenoses. Since there is no correlation between the degree of the stenosis and the pathophysiological changes of the cerebral circulation, OPG-Gee is of complementary value for the evaluation of the hemodynamic significance of a stenosis, established with the Doppler method.