The Research Of Interferon-γ Combined With Triamcinolone Acetonide Inhibiting Rabbit Proliferative Vitreoretinopathy

Proliferative vitreoretinopathy (proliferative vitreoretinopathy, PVR) is the causeof wound healing responses in the retina[1], and also is the cause of rhegmatogenousretinal detachment common complication after surgery and surgical failure. PVR isthe membrane cell proliferation formatting in the posterior vitreous and the front ofthe retina.PVR is a posterior vitreous membrane cell proliferation and the formationof the front of the retina. Its shrinking cause retinal traction and separation, and makethe successful treatment of retinal tear open or the a new hole formate.Itscharacteristics of easily relapsing and loss of vision caused by multiple surgeriesmake it become clinically important cause of blindness.Speaking of pathogenesis ofPVR, any clinical factor like the increase of the ocular inflammation and releasing ofthe retinal pigment epithelial cells in the vitreous cavity can stimulate the occurrenceof PVR[2].According to reports, the incidence of PVR in patients with retinaldetachment is the rate of5%to10%, with an average of7%[3]. Some existing pre-andintraoperative risk factors have closely linked with development of PVR. For example,the presence of preoperative PVR, had a history of intraocular surgery, excessive condensation or photocoagulation in the surgery, repeated surgery, intraoperativeapplication of air or SF6, postoperative bleeding and postoperative choroidaldetachment[4], the reset operation failure[5]. Thus, many clinical risk factors closelyare associated with PVR. Responsibility of ophthalmologist is in carefully selectedsurgical indications before the patients’ surgery and reasonably applicating ofeffective drugs to prevent PVR.Part I Building experimental animal model ofproliferative vitreoretinopathyPurpose：Observation and comparison their results of different kinds of methods toproduct the animal model of proliferative vitreoretinopathy.Method：12healthy rabbits were randomly divided into three groups, each eight eyes areexperimental eye. The first group (control group) intravitreal injection of saline, thesecond group (platelet group) intravitreal injection of platelet-rich plasma, and thethird group (macrophage group) intravitreal injection of allogeneic macrophages cellsuspension.Experimental eyes were observed by slit lamp microscope and directophthalmoscope after modeling4weeks, recording PVR grading situation.Results：The fourth week, macrophages group PVR levels were platelet levels higher thanlatelet group and the control group, the difference was statistically significant (P<0.05).Conclusion：Intravitreal injection of allogeneic macrophages to product PVR animal modelshas feasibility and repeatability, and better than intravitreal injection of platelet-richplasma. Part II Experimental study of interferon-γ inhibition ofproliferative vitreoretinopathyPurpose：Observation the inhibition of IFN-γ for proliferative vitreoretinopathy.Tounderstand the effects of IFN-γ intravitreal TGF-β1(TGF-β1) concentration changesin the progression of PVR.Method：12healthy rabbits were randomly divided into three groups, each eight eyes areexperimental eyes, the first group (control group) intravitreal injection of0.2ml ofsaline, the second group (model group) intravitreal injection of allogeneicmacrophage suspension0.1ml+0.1ml of saline, and the third group (IFN-γ group)intravitreal injection of allogeneic macrophage suspension0.1ml+0.1ml IFN-γsolution (1×104IU). Experimental eyes were observed by slit lamp microscope anddirect ophthalmoscope after modeling4weeks, recording PVR grading situation.Respectively, extracred0.1ml vitreous in the first3th day,7th day,14th day,28th dayafter modeling to detect cytokine TGF-β1concentrations By ELISA.Results：1．The fourth week, IFN-γ group PVR grade was lower than model group, higherthan the control group, the differences were statistically significant (P<0.05).2. During the PVR progress, rabbits intravitreal concentrations of TGF-β1showed regular changes, decreased after an initial increase. IFN-γ group of TGF-β1concentrations was lower than the model group, higher than the control group, thedifferences were statistically significant (P<0.05).Conclusion：IFN-γ can inhibit the development of PVR, and can inhibit the expression ofintravitreal cytokine of TGF-β1during the PVR progress. Part III Experimental study of interferon-γ combinedwith triamcinolone acetonide inhibiting rabbitproliferative vitreoretinopathyPurpose：Observation the prevention and treatment of IFN-γ combined with triamcinoloneacetonide for proliferative vitreoretinopathy. To investigate the treatment of PVRcombination of both whether has the effect of synergistic. To understand the effects ofIFN-γ intravitreal cytokines platelet-derived growth factor (PDGF) concentrationchanges in the progression of PVR.Method：16healthy rabbits were randomly divided into four groups, each four eyes forthe experimental eye, model group intravitreal injection of allogeneic macrophagesuspension0.1ml+0.1ml saline, triamcinolone acetonide group intravitreal injectionof allogeneic macrophage suspension0.1ml+0.1ml triamcinolone acetonideinjection, IFN-γ group intravitreal injection of cell suspension allogeneicmacrophages0.1ml+0.1ml of interferon-γ (1×104IU). Combined group intravitrealinjection of cell suspension allogeneic macrophages0.1ml+0.05ml triamcinoloneacetonide injection+0.05ml interferon-γ solution (0.5×104IU) Experimental eyeswere observed by slit lamp microscope and direct ophthalmoscope after modeling4weeks, recording PVR grading situation. Respectively, extracred0.1ml vitreous in thefirst3th day,7th day,14th day,28th day after modeling to detect cytokine PDGFconcentrations By ELISA. The first28days, the removal of the animal eye, paraffinsection, HE staining of retinal structure.Results：1．Four groups of mild vitreous opacities modeling in the first week, graduallyreduced with time. Vitreous transparent of control group during the observationperiod.2.The fourth week, the combined group PVR level was lower than the otherthree groups, the differences were statistically significant (P<0.05). TA group andIFN-γ group PVR levels were lower than the model group (P<0.05), with nodifference between the two groups statistically significant (P>0.05).Conclusion：IFN-γ in combination with triamcinolone acetonide may inhibit the progressionof PVR, and be better than medication alone.Combination therapy can inhibit the expression of PDGF intravitreal cytokines and be greater than medication alone.Speculate that IFN-γ and triamcinolone acetonide combination has a synergistic effecton the prevention of PVR.