Evaluation of the visual system in a rat model of chronic glaucoma using manganese-enhanced magnetic resonance imaging.

Abstract

This study aims to employ in vivo manganese-enchanced MRI (MEMRI) to evaluate dynamically the Mn(2+) enhancements along the visual pathway following an induction of ocular hypertension in a rat model of chronic glaucoma. Results showed an accumulation of Mn(2+) ions in the vitreous humor of the glaucomatous eye, with no statistical changes in the total retinal thickness but a possible occlusion of the ions at the optic nerve head. Meanwhile, there was a reduction in Mn(2+) transport in the glaucomatous optic nerve in the later stage of our model. Fewer enhancements in the visual cortex projected from the glaucomatous eye were also detectable. These may help understand the disease mechanisms, monitor the effect of drug interventions to glaucoma models, and complement the conventional techniques in examining the visual components.