Events Calendar

AME Department Seminar

Speaker: Anita Penkova , Postdoctoral Research Associate

Talk Title: Fluid Dynamics and Transport in the Posterior Segment of the Eye

Abstract: The fluid and solute transport in the posterior segment of the eye (vitreous humor and retina) takes place by complex transport mechanisms and processes which have not been fully examined and quantitatively explained in either healthy or diseased eyes. Among the goals of the ongoing research is to develop mathematical models based on experimental data for ocular fluid flow with twofold objectives: (1) to understand the fluid dynamics and transport in healthy and diseased eyes; and (2) to effectively deliver drug-based treatment for the latter. To effectively transport drugs to the retinal area, the transport mechanisms need to be understood and the relevant transport parameters (such as permeabilities and diffusion constants) in the various components of this highly complex structure need to be measured and quantified. To fully model the transport processes, the permeability of the RPE (retinal pigment epithelium) under various circumstances needs to be measured. While a healthy eye maintains a steady and well-regulated flow of fluids throughout the system, diseases can cause disruption to this process. Diseases such as diabetic retinopathy (DR) can cause partial blockage of the RPE and subsequent swelling due to fluid accumulation in the affected regions accompanied by vision impairment. The ongoing research includes the creation of DR conditions by exposing a bovine eye to 25 mM glucose for 24 hours, and measuring the permeability of the RPE together with an eye treated in 5.5 mM glucose as a control. With current experiments, it has been observed that exposure to glucose increases the transepithelial resistance, indicating some suppression of ionic pumping. These procedures are also being conducted for based experimentally grown fetal RPE cells (in-vitro).

Other interesting areas, particularly for drug delivery, include the transport in an aged human eye for which the vitreous humor has a heterogeneous character (gel and liquid) that complicates the mathematical modeling. While the gel may be treated as a porous medium described by Darcy flow, the remaining portion has to be modeled as Stokes flow. The current research on ocular drug delivery includes the modeling of transport through this complex structure and an experimentally-based development of the boundary conditions where the vitreous humor contacts the retina, the lens and the hyaloid, together with continuity conditions at the gel-liquid interfac


Host: Professor Satwindar Sadhal

More Info: http://ame-www.usc.edu/seminars/10-27-10-penkova.shtml

Location: John Stauffer Science Lecture Hall (SLH) - Room 100

Audiences: Everyone Is Invited

Contact: April Mundy

Event Link: http://ame-www.usc.edu/seminars/10-27-10-penkova.shtml