Thermal Effects on Fluid Mixing in the Eye

Abstract

Age-related macular degeneration (AMD) is the leading cause of central vision loss in the developed world. Wet AMD can be managed through serial intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) agents. However, sometimes the treatment is ineffective. Given that the half-life of the drug is limited, inefficient mixing of the injected drug in the vitreous chamber of the eye may contribute to the ineffectiveness. Here, we introduce thermal heating as a means of enhancing the mixing-process in the vitreous chamber and investigate parameters that potentially influence its effectiveness. Our in vitro studies reveal the importance of the heating location on the eye. A significant increase in the mixing and delivery of drugs to the targeted area (the macula) could be achieved by placing heating pads to induce a current, against gravity, in the vitreous. The presented results can potentially help in the development of a better strategy for intravitreal injection, subsequently improving the quality of patient care.

Mathematical Model of Macromolecular Drug Transport in a Partially Liquefied Vitreous Humor

“…The role of naturally occurring thermal effects is expected to be minimal in terms of intravitreal drug transport. Very recent studies by Huang and Gharib [21] have shown experimentally that an imposed thermal stimulus on a fully liquid vitreous (experimental simulation model), buoyant convection can be significant. Also, Narasimhan and Sundarraj [22] investigated the thermal effects in a fully liquid vitreous.…”