AIM:To observe the effect of dexamethasone (Dxm) on pathological changes of rabbit retina after vitreous hemorrhage. METHODS:Twenty-four white rabbits were randomly divided into normal saline control group(A),vitreous hemorrhage group(B) and Dxm treatment group(C),each with 8 rabbits. Group A was intravitreally injected 0.2mL physiological saline. Group B and group C were intravitreally injected 0.2mL autologous blood. Group A and B were given physiological saline 3mL/kg and group C was given Dxm 3mg/kg at 1st,24th and 48th hour after injection. Two rabbits (4 eyes) in each group were randomly killed on the 3rd,7th,14th and 21st day after animal model was established.RESULTS:Group A at all time points,group B on the 3rd,7th day and group C on the 3rd,7th and 14th day were retinal eumorphism. In group B,retinal ganglion cells and inner nuclear layer cell showed hydropic degeneration on 14th day and it was found that not only inner limiting membrane became thick and injury,but also retinal ganglion cells,inner nuclear layer,outer nuclear layer,inner and outer segments of photoceptor showed hydropic degeneration on 21st day. In group C,it was found retinal ganglion cells,inner nuclear layer showed hydropic degeneration on 21st day. CONCLUSION:Vitreous hemorrhage can cause hydropic degeneration of retina. Dxm can relieve the hydropic degeneration of retinal cells following vitreous hemorrhage.