Evaluation of retinal injury in a rat model of transient ischemic stroke

Stroke-associated ocular disorders are vision-threatening. This study was designed to evaluate in vivo retinal injury induced by transient global cerebral ischemia/reperfusion (I/R). A stroke-induced retinal injury model in Wistar rats was established by electrocoagulation of bilateral vertebral arteries, combined with transient ligation of the bilateral common carotid arteries. Rats were randomly divided into groups based on the time post cerebral perfusion (3 h, 24 h, 48 h, 72 h, and 7 days). Retinal injury was evaluated by histological analysis, examination of eye fundus, and TUNEL staining. The expression of protein kinase C-alpha (PKCα) and fibrillary acidic protein (GFAP) was determined using qRT-PCR and immunofluorescence analysis. Both retinal neurons and the vasculature underwent significant damage in the cerebral-I/R groups when compared to rats in the sham group. Moreover, when compared to non-stroke rats, TUNEL staining revealed signs of apoptosis in the retina after transient ischemic stroke was induced (P<0.001). In these rats, the expression of PKCα and GFAP in the retinas was enhanced and peaked at 72 h after induction of cerebral-I/R (P<0.001). In this study, we found that retinas are very susceptible to transient global cerebral-I/R injury. The expression of PKCα and GFAP may be implicated in the pathogenesis of ischemic stroke-induced retinal injury.