Retina Reduced Ocular Blood Flow as an Early Indicator of Diabetic Retinopathy in a Mouse Model of Diabetes

PURPOSE. To investigate ocular blood flow and visual function in the Ins2Akita diabetic retinopathy mouse model at early and late time points after onset of hyperglycemia. METHODS. Mice heterozygous for the Ins2Akita mutation, which become hyperglycemic at approximately 4 weeks old, were studied at 2.5 and 7.5 months of age, with age-matched wild-type littermates used as controls. Retinal and choroidal blood flows were noninvasively imaged at 42 3 42 3 400 lm using magnetic resonance imaging. Visual function was measured using optokinetic tracking to determine spatial frequency and contrast thresholds from the same mice. RESULTS. At 2.5 months, choroidal blood flow was significantly reduced (P < 0.01) by 20 % in Ins2Akita mice (n13) compared with age-matched controls (n16), whereas retinal blood flow and visual function were not significantly affected (P> 0.05)