| Central retinal vein occlusion (CRVO) is the third most common blinding vascular retinal disorder after diabetic retinopathy and branch retinal vein occlusion, often occurs in the elderly. The pathogenesis of CRVO is yet not well understood and no cure method can be recognized as effective. Besides ordinary medicines and the retinal laser photocoagulation treated for the neovascular complications, the studies of laser and surgical method are becoming the highlights, to re-build and recovery the retinal blood circulation. Creating chorioretinal venous anastomosis potentially offers a means of permanently bypassing the site of obstruction to venous outflow, to recovery the retinal blood circulation and to reduce the retinal ischemia. It is one of the methods curing the reason of CRVO and is demonstrated effective in non-ischemic CRVO patients using laser-induced chorioretinal venous anastomosis. Patients with ischemic CRVO have more severe situations and high risk factors of later neovascular complications occuring, the surgery of via a pars plana vitrctomy combined chorioretinal venous anastomosis can be the newest attempting treatment. Althought this surgery has been reported by a few doctors recently, the safety and effectivenessneed to be evaluated in further studies.In our study, the approach of the chorioretinal venous anatomosis(CRVA) in the model eyes with branch retinal vein occlusion, are induced by different surgical anastomosis procedures, in order to invest the effectiveness and safety and make a pilot clinic treatment exploration.Methods and materialsThe study was divided two ports: animal experiment and clinical study. 1. Animal experiment: prospective, controlled study(1)Animal: 32 eyes of 17 rabbits were chosen and randomly divided into normal group(N, 2 eyes), controlled group(C, 8 eyes), CRVA with simple venipuncture group (Ta, 6 eyes), CRVA with the non-absorbed material implant group (Tb, 6 eyes) and CRVA with the absorbed material implant group(Tc, 10 eye).(2) methods: all animal of one controlled group and three CRVA groups are performed pars plana vitrectomy by employed system general anesthesia. Two treatment points are performed at nasal and temporal retinal vein in each eye. Then additional procedures were including:C group: the rabbit BRVO model was built with intraocular diathermy to coagulate the retinal veins at nasal and temporal nearly closed to optic disc.Ta group: After retinal vein was occluded by the same method used as above, a venipuncture is performed in the locations away from the occluded site about 2/3 to 1 PD distance, a 20G needle tip was used to puncture the retinal vein and underlying retina and the Bruch' s membrane.Tb group: Choosing the same locations for CRVA points likely Ta group, aslit-like incision cut the retina and the Bruch' s membrane at one side of the venous vessel by MVR knife, then cut the venous vessel and implant a small piece of 7-0 prolene suture in the retinal incision.Tc group: The progress is similar to Tb group, but the implant material is a small piece of 5-0 monocryl suture.(3)Observe methods:Eye examination: 1, 2, 3 days, 1, 2, 4, 6 and 8 weeks after surgery.FFA and fundus colored photograph: 1, 2, 4, 8 and 12 weeks after surgery.Observations: retinal hemorrhage, venous tortuosity, visual degree of the vessel occluded spot and the establishment of the anastomosis function.(4)The method and the time of killing animals: 2 eyeballs were removed at the each experimental end of every group.(5)Histopathology examination: After fixation, the tissues were select at the anastomostic sites and d 4um sections were prepared for hematoxylin and eosin.2. Patient:(l)Eligibility criteria included: ischemic CRVO with decreased vision, macular edema, signed a consent form.(2)Exclusion criteria included: the patient had pan-retinal photocoagulation or grid pattern photocoagulation for macular edema, and suffered other eye diseases.(3)surgical method: local anesthesia, a standard 3-port pars p...
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