[Effect of arterial blood pressure on retinal hemodynamics--a videoangiography study on the problem of autoregulation of blood supply to the retina]

Abstract

In the videoangiographic study reported here the influence of blood pressure on retinal hemodynamics was investigated. Data for the study were obtained from a group of 377 patients. It was found that circulation times in the retina grow shorter as diastolic and arterial blood pressure rise. Diastolic blood pressure has a greater influence than systolic blood pressure on the circulation times in the eye. The increased velocity of retinal blood flow (as measured by the retinal circulation times) probably represents an autoregulative attempt to keep the blood supply in the retinal capillary system constant in spite of fluctuating blood pressure. When hypertensive changes in the retina or optic disk are ophthalmoscopically demonstrable, however, they are a sign that even the retinal autoregulation can no longer compensate for the effect of rising blood pressure on retinal hemodynamics: videoangiograms of this situation reveal an unmistakable slowing-down of retinal circulation, i.e., an increase in retinal circulation times.