Abstract: 【Abstract】 Objective To observe the expression of pax6 in retinal ganglion cells (RGC) and its significance after retinal ischemia-reperfusion (RIR) injury. Design Experimental study. Participants Rat model of RIR injury. Methods 30 adult female SD rats were randomly divided into 6 groups: group 1(n=5) normal control； group 2-6 (n=5 for each group) RIR injury groups (post injury 1 week, 2 weeks, 4 weeks, 6 weeks and 8 weeks respectively).  The intraocular pressure (IOP) of right eye was increased to induced RIR model. Pax6 expression was assessed by immunohistochemistry. Main Outcome Measures The expression of pax6. Results The positive rate of pax6 in RGC was (1.28± 1.41) % in control group, (0.99±1.23)% in 1w group, (14.45±2.72)% in 2w group, (50.88±4.73)% in 4w group, (71.00±4.72)% in 6w group and (78.80±4.62) % in 8w group. The difference of expression of pax6 in RGC among these groups was significant (F=1.350, P<0.0001). Compared with control group, the expression of pax6 in RGC was significant higher in 2w, 4w, 6w and 8w group (all P<0.0001), but not significant different in 1w group (P=0.835). Conclusion Pax6 expression was present in every layer of retina after RIR injury. RIR in rat induced activation of endogenous retinal stem cells. (Ophthalmol CHN, 2012, 21: 414-417)

Key words: retinal ischemia-reperfusion injury；pax6, stem cell