Modification of retinal hemodynamics by induced changes in intraocular pressure: a videoangiographic study

Abstract

This study used videoangiography to observe the effect of artificially produced rises in pressures in the eye on the haemodynamics of the retinal vessels. The intraocular pressure was increased with Müller's ophthalmodynamometer in stages of 10 mm Hg. A demonstrable effect upon the arterial and early venous times as well as the arm-retina time appeared. A constant rise in pressure appeared in the acute experiment: here the circulatory times more than doubled when intraocular pressure rose from under 20 mm Hg to 40 mm Hg. Above 50 mm Hg a further, statistically highly significant increase in the circulatory times of the eye became evident. The retinal vessels were obliterated in the rule at intraocular pressures above 50 mm Hg. When the data on changes in retinal circulation acquired by videoangiography are compared with the data on blood volume flow-through reached with microspheres, both methods reveal a good correlation. This shows that the determination of circulatory times in the eye is also a source of information on blood volume flow.