Comparison of the pneumooculoplethysmography (GEE) and the digitalized pulse timing oculoplethysmography (ZIRA)

Comparative study of the pneumooculoplethysmography (OPG/Gee) and the digitalized pulse timing OPG (Zira) was conducted by analysis of 100 patients who had both OPG/Gee and Zira and carotid arteriograms. Both units were valuable in diagnosis of normal carotid arteries, 94 per cent for Gee and 89 per cent for Zira. The Gee unit was more valuable in the diagnosis of unilateral significant carotid stenosis, 90.3 per cent versus 75 per cent for the Zira machine. The Gee unit was also very valuable in detecting bilateral carotid stenosis, 90.4 per cent but the Zira unit was limited in this group; i.e., 60 per cent only. The overall accuracy of the OPG/Gee was superior to the OPG/Zira, 92 per cent versus 80 per cent.