Effect of Pulsatile Flow in Retinal Microvascular Cells

Systemic vascular abnormalities involving impaired regulation of retinal vessels are considered to play a role in glaucoma, particularly low-tension glaucoma (LTG). The vascular supply of the optic nerve head is a capillary network, and factors that affect vascular tone in the endothelial and pericyte cells of this network play a key role in the regulation of optic nerve blood flow. This proposal focuses on examining the effect of hemodynamic forces (pulsatile flow and shear stress) on the retinal vasculature and also on the systemic vessels of LTG patients. Dr. O’Brien is examining the effect of high and low flow rates on the expression of vasodilators and vasoconstrictors in retinal endothelial cells in culture, as well and the effect on signaling pathways in these cells. He is also studying the expression and function of enzymes responsible for the synthesis of vasodilators and vasoconstrictors in systemic vessels obtained from gluteal fat biopsies in LTG patients. He is isolating and co-culturing endothelial and smooth muscle cells from the vessels in LTG patients to study the effects of high and low pulsatile flow rates. The results of these experiments will provide important information of the regulation of vascular tone, and will enhance our understanding of the underlying vascular abnormalities in LTG.