Experimental Research On Inhibition Of Different Concentration Avastin For Cornea Neovascularization

Corneal neovascularization(CNV) resulting in the structure of the eye and function of view, is one of the main reasons for blindness.Previous studies revealed that vascular endothelial growth factor (VEGF) plays an important role in CNV shaping.lt has been said that avastin can inhibitor CNV, showing its clinical application prospect.However, the better effective concentration of avastin is not determined.This research observes the inhibitorition of three concenration of avastin for CNV induced by corneal alkali burn in rats, providing relevant experimental evidence for clinical prescription.Part I Dynamic observation on the inhibition of different concentration avastin for corneal neovascularizationObjective Observing the effect of avastin for CNV induced by corneal alkali burn is to find the better concentration of avastin.Methods Corneal alkali burn model was established in rat.All rats were divided into 4 groups randomly:control group,experimental group 1,experimental group 2 and experimental group 3,each group including 15.Control group was treated by subconjunctival saline solution(0.05mL) immediately and the seventh day after corneal alkali burn. Experimental group 1 was treated by subconjunctival avastin0.05ml (2.5mg/ml);experimental group 1 was treated by subconjunctival avastin0.05ml (12.5mg/ml); experimental group 1 was treated by subconjunctival avastin0.05ml (25mg/ml).Each experimental group was treated by subconjunctival equivalent and homologous concentration of avastin immediately and the seventh day after corneal alkali burn.Allgroups were observed neovascularization and compared the area of CNV on the 7th,14th,28th day after corneal alkali burn.Five rats corneal of each group were taken for histopathological examinations (HE)by electron microscope on the 7th,14th,28th day.Results The corneal neovascularization areas of experimental groupl,2 and experimental group 3 was smaller than control group (P<0.05),and the CNV corneal areas of experimental group 2 and 3 was smaller than control group at day 7,14,28 after cautery (P<0.05).There was no significant difference between experimental group 2 and 3 at the correspondent time(P>0.05).Conclusions In the three concentration 2.5mg/ml,12.5 mg/ml and 25 mg/ml,12.5mg/ml avastin more effectivly inhibite CNV ofter corneal alkali burn. Subconjunctival avastin that have no toxicity and adverse effect found in the body and the local.Part II Effect of the expression of different concentration avastin for VEGF in the cornealObjective Observing the effect of avastin for corneal VEGF after corneal alkali burn is to discuss the mechanism of the inhibition of avastin for CNV.Methods Corneal alkali burn model was established in rat.All rats were divided into 4 groups randomly:control group,experimental group 1-. experimental group 2 and experimental group 3,each group including 15.Control group was treated by subconjunctival saline solution(0.05mL) immediately and the seventh day after corneal alkali burn. Experimental group 1 was treated by subconjunctival avastin0.05ml (2.5mg/ml) experimental group 1 was treated by subconjunctival avastin0.05ml (12.5mg/ml); experimental group 1 was treated by subconjunctival avastin0.05ml (25mg/ml).Each experimental group was treated by subconjunctival equivalent and homologous concentration of avastin immediately and the seventh day after corneal alkali burn. Five rats corneal of each group were taken,and expression of VEGF in the corneal was detected by immunohistochemistry (IHC)on the 7th,14th,28th day after corneal alkali burn.The we compared the positive rate of the corneal VEGF in groups.Results There were significant difference between control group and experimental group and the positive rate of the corneal VEGF in control group was more than that in experimental groups (P<0.05). The positive rate of the corneal VEGF in experimental group 1 was more than that in experimental group 2 and 3 (P<0.05),then there was no significant difference between experimental group 2 and 3 at the correspondent time(P>0.05).Conclusions CNV induced by corneal alkali burn is closely related with VEGF, and avastin can clearly reduce the expression of the burned cornea VEGF. In the three concentration 2.5mg/ml,12.5 mg/ml and 25 mg/ml,12.5mg/ml avastin more effectivly inhibite the cornea VEGF ofter cautery.