Manganese-enhanced MRI studies of alterations of intraretinal ion demand in models of ocular injury

Abstract

PURPOSE. To provide proof-of-concept that the extent of intraretinal manganese uptake after systemic MnCl2 injection, detected with manganese-enhanced MRI (MEMRI), assesses alterations in intraretinal ion demand in models of ocular insult. METHODS. In Sprague-Dawley rats, retinal ion demand and thickness were measured from MEMRI data collected before, 4 hours after, or 1, 3, and 7 days after intraperitoneal injection of MnCl2. Choroidal contribution or blood-retinal barrier permeability surface area product (BRB PS′) was determined using MRI after Gd-DTPA injection. Ocular injury was evaluated 24 hours after intravitreal injection of phosphate-buffered saline (PBS, vehicle) or PBS + ouabain,..