Convection-Enhanced Intravitreous Drug Delivery in Human Eye

Abstract

Two-dimensional computational model has been developed for simulation of convection-assisted drug transport during intravitreal drug delivery for vitrectomized human eye. The convection current in vitreous humor was induced by laser heating. The model drug fluorescein was placed initially in different positions inside the vitreous. The transport of drug, taking the natural convection flow into account, was numerically solved using appropriate conservation equations. For a simulation period of 60 min, the convection-assisted diffusion increased the average drug mass fraction in the retinal target region by 5.7 times compared to the pure diffusion model, in case of central depot. Even for low diffusivity high molecular weight compounds, the convection in vitreous proved useful in enhancing the transport across vitreous. The study showed that inducing convection in vitreous could be potentially used for drug delivery in eye. Also laser heating could be explored as an option to enhance the delivery of drug to the posterior segment of the eye.