Evaluation of internal carotid stenosis with the Chronopulse, an automated ocular pulse arrival time recorder

The diagnostic value of ocular pulse time measurement with the Chronopulse was evaluated in 67 patients who had carotid arteriography. The diagnostic accuracy of 85.5 percent was comparable to that obtained by two other groups using a different timing device. Identification of bilateral stenosis was the major problem encountered and resulted from measuring the external carotid circulation at the ear. Ocular pneumoplethysmography performed in the same patients yielded a higher diagnostic accuracy than the pulse timing, and combining the two did not enhance the results. Therefore, we recommend that the Chronopulse not be used as part of the routine ocular pneumoplethysmographic examination but that it be reserved for selective application.