Einflüsse des orbitalen venendrucks auf die augendruckregulation und die augendurchblutung

The goal of this work is to characterize the relationship between the orbital venous pressure (OVP) and ocular hemo- and hydrodynamics. Continuous measurements of OVP, episcleral venous pressure (EVP), arterial pressure (MAP), intraocular pressure (IOP) and choroidal blood flow (ChorFlux) were performed in anesthetized rabbits while blood pressure was manipulated mechanically. The measurements revealed linear relationships between OVP/IOP, OVP/ EVP and IOP/EVP. Venous resistance calculations indicate a passive behavior of the pathway between the intraocular choroidal veins and the orbital venous sinus. The pressure drop of 6 mm Hg from the episcleral veins to the orbital venous sinus at baseline is another significant finding of this study. We conclude that the involvement of the orbital venous pressure in regulatory mechanisms of intraocular pressure and ocular hemodynamics might be important and should be considered in future studies.