The Protection Of Retinal Ganglion Cells And Optic Nerve In High Intraocular Pressure Animal Model By BFGF

Objective:To evaluate the protection by basic fibroblast grown-factor to retinal ganglion cells and optic nerve in high intraocular pressure of tabbies.Method:Thirteen rabbits(26 eyes)were divided into experimental(12 eyes)and control group(12 eyes)randomly,HPMC was injected into anterior chamber to make high IOP model of rabbits.In experimental group 0.1ml of bFGF(2000U)was injected into one vitreous randomly of each rabbit and the same volume PBS into the other vitreous consisted of control group.The left rabbit was the normal control group (2 eyes)without any injection.We observed the IOP at the same time everyday,if IOP was less than 30 mmHg which lasted two days,CMC had to be given again. bFGF or PBS was injected again at 7 days,14days,21days post-surgery in each group.The Photos of the fundus and F-ERG were obtained before the operation,after the operation 7th,14th,21th,28th-days separately.The retinas and potic nerves were removed from the enucleated eye at 7days,14days,21days and 28days post-surgery. The number of surviving RGCs and fibers optic nerve were calculated under the optical microscope and the Electron microscope.Result:Performance Each group of rabbits were seen to varying degrees inflammatory response,such as congestive conjunctiva,corneal edema,after seven days can be dissipated.The IOP The average of IOP was above 30mmHg and it kept 5 to 7 days.There is no difference between experimental group and the control group(P＞0.05).The change of the Fundus 7days post-surgery,there in no change in both groups.Two weeks post-surgery,in the control group,blood vessels became curved and the optic disc became pale.Three weeks after,in the control group we can find the optic cup expand and the blood vessels curve,while in the experimental group,the optic cup expand but the vessels were steel normal.There is no difference in C/DAR between two groups before the creat model and the first post-surgery weeks(P＞0.05),but 14days later there was difference(P＜0.05).Electroretinogram physiology In the standar test of scotopic rod response, scotopic combined rod-cone response,scotopic oscillatory potentials,photopic single-flash cone response and photopic 30Hz flicker cone response;seven days post-surgery,we could find the total oscillation amplitude of a wave,b wave and Ops in the control group was lower than that in the experiment group(P＜0.05).In the control group or the experiment group every wave and time became lower and longer as each time(P＜0.05).The pathological changes The retinal tissue of normal control group shew clear layers,including the inner limiting membrane,nerve fiber layer,ganglion cell layer,inner plexiform layer,inner nuclear layer,outer plexiform layer and the outer nuclear layer.In the ganglion cell layer,the ganglion cells were well-arranged and looked like each other.The optic nerve fibre array was neat and the gap was even.Severn days later,the most obvious change was the thickness of the ganglion cells layer.The control group and the experimental group both shew the lost of the RGCs and Nf,but there were difference between the two groups(P＜0.05);the control group's RGCs began to apoptosis.Optic nerve spongiocyte arranged disorder and optic nerve fiber became swell in the Control group's.After 4 weeks,the RGCs were nearly died out in the control group,while some still survive in the experimental group.About cross section of,the optic nerve presented the massive vacuoles and the marrow shell type in the control group.Optic nerve fiber present a big piece of necrosis and the spongiocyte proliferation.The cells and Nf in the inner nuclear layer were also less than before.Ops wave in RGCs 20.12%decrease when there were changes,the most sensitive in examinations of ERG.The Electron microscope Four weeks later,in the control group,the quantity of cell organ in Cytoblastema reduced,Line plastochondrias denaturize,the arrangement of axon was disordered and the Myelinic membrane denatured.While in the experiment group,the Capillary and micro silk were swelling but we could find some of them in the axon.Conclusion:1.Photos of the fundus,data of F-ERG and the pathological examination show that the models were doing well.2.In this high intraocular pressure animal model,the apoptosis of RGCs and optic nerve due to the time duration.3.RGCs,Nf reduced rate,Ops wave,b-earlier there were Changes in the first of High intraocular pressure animal model,then the CD / DAR have a significant change,a wave have a significant change in the latest.Ops wave is observed the rate of RGCs reduced of the most sensitive indicators.4.In this model,the results demonstrate that bFGF could maintain the survival of protection on retinal ganglion cells and optic never.