PURPOSE:To identify visual function changes and histologic damage in the rat retina after ischemia reperfusion insult.
METHOD:Ischemia reperfusion damage was induced in Sprague-Dawley rats by elevating the intraocular pressure to 110 mm Hg for 60 minutes. Visual function was evaluated by flash visual evoked potentials (fVEPs) and flash electroretinography (fERG) 1, 3, 7 days post ischemic insult. RGCs were quantified in retinal flatmounts 7 days after ischemia reperfusion and TUNEL assay was used to evaluate apoptosis of retinal neurons.
RESULTS:There were alterations in both of amplitude and latencies of P1-N1 and N1-P2 waves of VEP 3 and 7 days post ischemia. The amplitudes of P1-N1 and  N1-P2 waves were significantly reduced in all post-lesion-days (p < 0.01). In ERG recordings, both a-wave and b-wave amplitudes decreased significantly after the insult (p<0.01). The number of RGCs decreased 7 days after ischemia reperfusion  (p<0.01) with visible retinal thick loss. The TUNEL positive cells were observed in RGC Layer and external nuclear layer on day 1 and 3 following retinal ischemia reperfusion.
CONCLUSIONS:The retinal ischemia reperfusion causes significant damage to visual function and the whole retinal tissues especially neurons. It might serve as a useful model to neuroprotection studies in vivo.