MR studies of retinal oxygenation.

In this paper, we summarize the development and application of two novel magnetic resonance based measurements of retinal oxygenation in experimental models of retinopathy, including diabetic retinopathy and retinopathy of prematurity. We use 19F-NMR and a small (microl) perfluorocarbon drop positioned in the preretinal vitreous space to make PO2 measurement of the inner retina. In addition, we use magnetic resonance imaging (MRI) to accurately and non-invasively measure the change in the preretinal PO2 (DeltaPO2) following the shift from breathing room air to a hyperoxic inhalation challenge. The advantages and disadvantages of each method are discussed. New applications of these techniques in the newborn rat and adult mouse are presented. We expect such studies to motivate future MRI oxygenation studies of human retinopathy, including diabetic retinopathy and retinopathy of prematurity.