Correlation of axial blood velocity to microvascular diameter in the human eye in vivo
What is it about?
The axial blood velocity (Vax) correlation to microvessel diameter (D) was studied at 104 different postcapillary venules (4 μm < D < 24 μm) and 30 different precapillary arterioles (6 μm ≤ D ≤ 12 μm) in the human conjunctiva of normal healthy humans. In general, higher diameters suggest higher velocities but this general principle does not seem to be valid for small variations of diameter. Answering the question of how small these variations might be, for humans, was one of the targets of this work. Another target of this work was to give average values of Vax of healthy individuals in correspondence to specific diameter changes.
Why is it important?
1) The results of this work could be useful to other experimental investigations developing new semi-automatic or fully automatic velocity measurement techniques. 2) Average Vax values could have clinical or diagnostic application. For example, significant differences in the Vax of the conjunctival microcirculation have been reported after the application of contact lenses. 3) Vax and other hemodynamic parameters are essential in many research areas such theoretical models on vascular design, the number of chemicals exchanged between blood and tissue, the micro mechanobiology of endothelium cells in health and disease and vascular targeted drug carriers. Furthermore, hemodynamic parameters are important for the realistic design of in vitro apparatuses and assays for the study of angiogenesis, the blood-brain barrier, the endothelial response and cell adhesion. Cell adhesion is a broad topic implicated in many research areas comprising the attachment of circulating tumor cells, tissue engineering, and regenerative medicine.