K Orihashi, Y Matsuura, T Sueda, et al (Hiroshima Univ, Japan)
Flow Velocity of Central Retinal Artery and Retrobulbar Vessels During Cardiovascular Operations. J Thorac Cardiovasc Surg 114: 1081-1087, 1997.
It is imperative to monitor blood flow and blood pressure during cardiovascular surgery to avoid inadequate cerebral perfusion. The current study assessed blood flow through the central retinal artery, which has been shown to reflect an obstruction of the carotid artery.
Systolic B.P. was corelated with maximal velocity. The mean BP-axis intercept, or critical closing pressure, was 35.8mm Hg.
Orbital vessel monitoring helps to establish the critical closing pressure of the central retinal artery and confirms patency of the circle of Willis. During cardiovascular oeprations, the eye can serve as “an acoustic window” to intracranial blood flow.