Biomathematics Seminar: Oscillatory motion of the vitreous humour within the eye
7 February 2012 14:00 in Department of Mathematical Sciences
We study a model of the vitreous humour of the human eye in order to investigate typical stresses induced on the retina by motions of the eye, which may play a role in retinal detachment (a condition that can lead to loss of sight) and also mixing of drugs injected into the vitreous humour. The vitreous humour itself is contained in the vitreous cavity, which has an approximately spherical shape, and it has complex viscoelastic properties. We consider its behaviour under repeated torsional oscillations, such as those the eye makes whilst reading. We start by approximating the vitreous chamber as a spherical cavity and the vitreous humour as a Newtonian fluid and we show that there is a steady streaming component of the flow, whose role is likely to be dominant in mass transport. We extend the model to allow for a non-spherical vitreous chamber, which leads to additional vortices in the flow. The results show that the shape of the domain is likely to play a very important role in mass transport. Finally we consider a viscoelastic model of the vitreous humour. We again simplify to a spherical chamber and consider the flow in a stationary sphere starting from a prescribed non-zero velocity, which can be decomposed into a superposition of modes. Using two proposed models of the rheology we then consider periodic flow in the torsionally oscillating sphere (considered in the first part of the talk). We show that there are resonant frequencies at which particular modes of oscillation are excited. Finally we discuss the real geometry of the vitreous chamber, and analyse the effect of a small departure from the spherical shape.
Contact firstname.lastname@example.org for more information