Purpose: Early subnormal retinal oxygenation response to a hyperoxic provocation (DeltaPo2) is strongly associated with subsequent experimental diabetic retinopathy and can be reversed by drug treatments started with the induction of diabetes. It is not yet known whether drug treatment can reverse an established subnormal DeltaPo2.
Methods: Retinal DeltaPo2 was measured in two separate experimental paradigms in streptozotocin-induced diabetic rats.
Purpose: To test the hypothesis that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) provides a useful in vivo measure of passive blood retinal barrier permeability surface area product (BRB PS) in experimental diabetic retinopathy.
Methods: BRB PS (cm(3)/min) was measured using DCE-MRI and Gd-DTPA (MW 590 Da) in urethane-anesthetized control rats, sodium iodate-treated rats, rats receiving intravitreally injected human serum albumin (HSA) or vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), or in rats that were diabetic for 2, 4, 6, or 8 months.
Results: Sodium iodate-treated rats exhibited an eightfold increase (P < 0.