Visualizing ocular lens fluid dynamics using MRI: manipulation of steady state water content and water fluxes

• DOI: 10.1152/ajpregu.00173.2011
• Publication Date: 2011-05-19T00:44:26Z
• Authors: Ehsan Vaghefi; Beau P. Pontre; Marc D. Jacobs; Paul J. Donaldson
• Keywords: Concentration gradient

Studies using various MRI techniques have shown that a water-protein concentration gradient exists in the ocular lens. Because this is higher core relative to lens periphery, refractive index established To investigate how profile maintained, bovine lenses were incubated different solutions, and changes ratio monitored proton density weighted (PD-weighted) imaging absence presence of heavy water (D(2)O). Lenses artificial aqueous humor (AAH) maintained steady state gradient, but incubating high extracellular potassium (KCl-AAH) or low temperature (Low T-AAH) caused collapse due rise content visualize fluxes, D(2)O, which acts as contrast agent. Incubation KCl-AAH T-AAH dramatically slowed movement D(2)O into did not affect outer cortex. seemed preferentially enter cortex at anterior posterior poles before moving circumferentially toward equatorial regions. This directionality influx was abolished by T-AAH, resulted homogenous Taken together, our results show actively fluxes poles.