Morphological changes and expression of apoptosis-related gene bax in retina in rabbits after hemorrhagic retinal detachment

Objective To observe the morphological changes and the expression of bax in a rabbit model after hemorrhagic retinal detachment(HRD),and to investigate the role of apoptosis in HRD.Methods Fourty-two eyes of 21 rabbits were divided into two groups randomly.In experimental group,HRD models were established with subretinal injection of autologous blood 0.2 mL,and in the control group,the heparine sodium was injected correspondingly.Four eyes of other 2 rabbits were set as the normal control group.The number of retinal ganglion cells and the thickness of the inner retinal layers were measured by HE staining method 1 hour and 1 day,3 days,7 days,10 days,14 days and 28 days after the establishment of HRD and RD,respectively.The expressions of bax gene protein and mRNA in the models of HRD and RD were evaluated with immunohistochemistry and in situ hybridization.Results Ten days,14 days and 28 days after the establishment of models,the thickness of the inner retinal layers and the number of retinal ganglion cells in experimental group were obvious fewer than those in the control group(P0.05).There were positive cells one day after establishment of HRD.There were significant expressions of bax 1 day to 7 days after HRD and the positive cells peaked on the 3rd day.On the 1st day,3rd day,7th day,the number of positive cells in experimental group were more than that in the control group(P0.001).Conclusion The retinal damage of HRD were severer than that of RD,and showed a time-dependent manner and forward process.The expression of bax implicited that apoptosis might play an important role in mechanism of retinal injury after HRD.