Elastic jump propagation through the retinal circulation

Retinal hemorrhage (bleeding of the retinal circulation within the eye) can arise from a traumatic brain injury and is also a clinical identifier for ‘Shaken Baby Syndrome’. Head trauma causes a pressure increase within the Cerebrospinal Fluid (CSF), which is imparted to the Central Retinal Artery and Vein when they pass across the CSF space. These blood vessels then enter the eye via the optic nerve, carrying the imparted impulse into the eye where it can cause vessel bursting hemorrhage.

Using a four-compartment model, we will examine how the arrangement of the vessels as they enter the eye influences the shape and amplitude of the pressure wave which enters the retinal circulation. The wave has a steep front and long tail behind. The front can steepen sufficiently to generate an elastic jump (shock wave) in the blood vessel, which then spreads through the network. We use a novel analytical method to examine how this elastic jump propagates through a network of elastic blood vessels, comparing with numerical results from a shock capturing, upwind finite volume scheme.