AIM Seminar: Modeling oxygen transport and flow regulation in the human retina

Impairments in retinal blood flow and oxygenation have been shown to contribute to the progression of glaucoma. In this study, a theoretical model of the human retina is used to predict blood flow and tissue oxygenation in retinal vessels and tissue for varied levels of intraocular pressure and in the presence or absence of blood flow regulation. The model includes a heterogeneous representation of retinal arterioles and a compartmental representation of capillaries and venules. A Green’s function method is used to model oxygen transport in the arterioles, and a Krogh cylinder model is used in the capillaries and venules. Model results predict that both increased intraocular pressure and impaired blood flow regulation can cause decreased tissue oxygenation. Results also indicate that a conducted metabolic response mechanism reduces the fraction of poorly oxygenated tissue but that pressure- and shear stress-dependent response mechanisms may hinder the vascular response to changes in oxygenation. Importantly, the heterogeneity of the vascular network demonstrates that average values of tissue oxygen levels hide significant localized defects in tissue oxygenation that may be involved in glaucoma. Ultimately, the model framework presented in this study will allow for future comparisons to sectorial-specific clinical data to help assess the potential role of impaired blood flow regulation in ocular disease. Speaker(s): Julia Arciero (IUPUI)