| Retinal neovascularization (RNV) is a major cause of vision loss that is attributable to many ocular fundus diseases, such as age-related macular degeneration, diabetic retinopathy and retinal vein obstruction.The pathogenesis is very complex and so far has not been elucidated completely. Many experts have raised many new views for pathogenesis and treatment methods of ocular fundus blood vessel diseases.The Avastin of VEGF antibody has been increasingly applied and received spective results . Avastin was developed by American Biology Technology Company Genentech Company. Its molecular structure mainly is composed by human's frame area IgG1 and the mouse monoclonal antibody antigen union supplementary decision area,.It can prevent VEGF and the blood vessel endothelial cell surface acceptor union,thus restraining endothelial cell mitosis and hindering the formation of the newborn blood vessels.The study of the effect of Avastin for RNV is aimed at establishing retinal neovascularization model in rabbits and evaluating its effect through the injection of Avastin and providing new evidences.Materials and methodsHealthy and colored domestic rabbits were selected for experimental objects, using electric coagulation device to coagulate the retina blood vessels, and rabbit RNV model was established. Two weeks later, examined with FFA and microscopic examination, the newborn blood vessels were formed .36 rabbits(72eyes) were randomly divided into two groups: control group and treated group, treated group was injected with Avastin 1.25mg/0.05ml,while control group with BSS 0.05ml. 12 rabbits were sacrificed and removaled eyeballs in 1,2 and 4 weeks separately after injection. 10 rabbits were made paraffin section and 2 rabbits were examined by electron microscope. VEGF and Fâ…§-Rag expression were detected with immunohistochemistry.oculus normalis 3 eyes belong to normal control group.Results1. After 2 weeks of electric coagulation of binocular retinal vessels beside optic disc .examined with FFA and microscopic examination, the newborn blood vessels were formed. 80 eyes were treated through electric coagulation, except externally formal 6 eyes with no RNV occurring and scleral perforation 2 eyes. The RNV establishment rate was 90% .2. Fluorescence leakage disappeared after 1 week in treatment group and new vessels reviving can not be seen after 2 and 4 weeks of reexamination; FFA showed earlier period (artery prophase or arterial phase ) developing appeared; Fluorescence leaked quickly and later period hyper fluorescence emerge after 1, 2 ,4 weeks in control group. Ocular fundus color photograph showed retina new-born vessels disappeared after 1 week in treated group; No new vessels can be seen after 2-4 weeks. The area of retina new-born vessels enlarged in control group when observing fundus after 1, 2 ,4 weeks.3. Retina new-born vessels of pigment rabbits were injected with Avastin 1.25mg/0.05ml. Compared with the control group after 1,2,4 weeks, the test showed VEGF and Fâ…§-Rag expression of experiment group decreased.4. Compared with the control group after 1,2,4 weeks , light microscope showed Endothelial cellular nucleus numbers which breakthrough membrane of retina decreased .The observation showed no obvious dysfunction.Conclusions 1. Retinal neovascularization model in rabbits can be established after 2 weeks with coagulating retinal vessels on both side of optic disc.2. FFA and ocular fundus color photograph are valid techniques for the observation of RNV disappearance before and after treatment with Avastin.3. Light and electron microscope show that Avastin can treat RNV but no obvious evidence of toxicity transformation.4. Avastin is capable of resolution experimental retinal neovascularization in rabbits; It has curatively therapeutic effect and can be used as an effectively clinical method. |
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