Optic nerve injury model in rats set up by fluid percussion brain injury device / 中华眼底病杂志

ABSTRACT

Objective To observe whether the animal model of optic nerve injury in rats can be set up by fluid percussion brain injury device (FPI) or not.Methods Seventy-one healthy female Wister rats were randomly divided into 2 groups,inlcuding model group with 66 rats and control group with 5 rats.The rats in model group were randomly divided into 3 groups.Eight rats in group 1 were examined by flash-visual evoked potential (F-VEP) and magnetic resonance imaging (MRI) examines before and 1,3 days,1,2,4,6,and 8 weeks after injury;56 rats in group 2 were randomly divided into 7 subgroups with 8 rats in each subgroup,and were detected by histopathologieal and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) apoptosis examines 1,3 days,1,2,4,6,8 weeks after injury;2 rats in group 3 were examined by electron microscopy 4 and 8 weeks aher injury.According to the degree of injury,the injured eyes were divided into 2 groups including severe injury group with the beat pressure of (699.14±60.79) kPa and mild injury group with the beat pressure of (243.18±20.26) kPa.The right and left eyes in rats in each group were in severe and mild injury group,respectively.Results One day after injury,the latency duration of F-VEP prolonged in severe injury group,wich differed much form which in the normal control group (P<0.05);the amplitude was gradually reduced during the first 2 weeks after injury and kept steady after that (P>0.05).The latency duration prolonged in mild injury group,and its difference with the normal control group was statistically significant (P<0.05);the amplitude was gradually reduced during the first 4 weeks after injury and kept steady after that (P>0.05).The abnormal high signal could be seen on optic nerve 1 day after injury,and was still obvious 8 weeks later.The results of histopathological examination showed ruptured capillary in ganglion cell layer 1 day after injury;retinal ganglion ceils without nucleus could be seen 4 weeks after injury.The apoptosis of positive cells was found in each layer of the retina 3 days after injury.TUNEL results indicated that the number of apoptotic positive cells increased significantly 1-2 weeks after injury.Conclusion An animal model of optic nerve injury can be successfully set up using FPI in rats.