Comparison of various oculoplethysmography modalities.

This article compares the accuracy of commonly used oculoplethysmography (OPG) equipments--OPG/Gee, OPG/Kartchner, and OPG/Zira--in the detection of significant carotid stenosis. The first 200 patients (400 carotid arteries) with readily available carotid arteriograms were selected from each of the following categories: OPG/Kartchner, OPG/Gee, and OPG/Zira, making a total of 600 patients. The radiologic findings were divided into two categories: the first included patients with normal carotid arteries or vessels with less than 50% stenosis, and the second included patients with carotid stenosis greater than or equal to 50%. The results of OPG/Zira, OPG/Kartchner, and OPG/Gee are listed respectively: diagnostic sensitivity of 88.88%, 92.6%, and 96.0%; diagnostic specificity of 86.77%, 90.7%, and 91.8%; false positive rate of 6.0%, 5.1%, and 3.6%; false negative rate of 22.7%, 13.0%, and 8.9%; overall diagnostic accuracy of 88.25%, 92.0%, and 94.8%; and accuracy in determining bilateral carotid stenosis of 66.0%, 79.0%, and 89.5%. We concluded that the three machines were valuable in the diagnosis of normal carotid arteries and significant unilateral carotid stenosis. However, the OPG/Gee had slightly better overall accuracy and was more valuable in the diagnosis of significant bilateral carotid stenosis. The OPG/Kartchner had the advantage of being applicable in patients with extreme hypertension and cardiac arrhythmias. The OPG/Zira was limited in the diagnosis of bilaterally significant carotid stenosis.