Objective:To investigate the mechanism of intravitreous injection with conventional dosage of domestic triamcinolone acetonide(TA)for retinal edema in rabbits. Methods:The model of retinal edema was established with argon laser photocoagulation to retinal vein in fourty-eight healthy purebred New Zealand white rabbits. The right eye of A group wasn’t injected anything as the control group

and the right eye of B group was injected with TA suspension 4mg(0.1ml)as the TA group. Six animals were killed randomly 3 days

1 week

2 weeks

and 1 month after the injected. The changes of the retinal edema were observed by light microscopy. The expression of VEGF mRNA and IL-6 were observed respectively by hybridization in situ and immunohistochemical method. Results:The model of retinal edema was established in all the eyes. The pathologic changes in TA group were better than that in control group. The expressions of VEGF mRNA and IL-6 in control group were higher than in TA group (P<0.05). Conclusion: Intravitreous injection of domestic TA may low the expression of VEGF mRNA and IL-6 in the model of retinal edema effectively and protect the retina.