Abstract
Purpose: :
To study the experimental rat retinal blood vessel permeability after laser–induced retinal vein occlusion and the effects of normal and lower level of blood estrogen on it.
Methods: :
Thirty–six female Sprague–Dawley rats were randomly divided into three groups: First, the normal control group. Second, sham–ovariectomy group. Third, ovariectomy group. In all group, smear test of vaginal epithelium was used to verify decreased blood level of estrogen one week after operation. The serum estrogen concentration of each rat in all groups was tested by chemiluminescence’s way. Then, retinal vein occlusion model was established by photodynamic thrombosis in one eye of each SD rat. Fluorescein angiography and Evan’s Blue perfusion were used to evaluate the blood–retinal barrier quantitatively and qualitatively respectively after two weeks.
Results: :
One week after sham–ovariectomy or ovariectomy, keratinized epithelium of vagina reduced significantly in ovariectomy group, but insignificant in sham–ovariectomy group and normal control group. Serum estrogen concentrations of the rats in the ovariectomy group were 45.09±10.14pmol/L, which of sham–ovariectomy group and normal control group were 138.04±25.69pmol/L, 135.26±29.04pmol/L respectively. Serum estrogen concentrations of rats in the ovariectomy group were significantly less than those of the other groups (p=0.000). Animal model of retinal vein occlusion was successfully established through photodynamic thrombosis, which was verified by blood stasis, black thrombosis and peripheral retinal hemorrhage during operation and fluorescein angiography after two weeks later. The blocked retinal veins became dilated and tortuous in angiography, and there was leakage from the blocked vessels in the late phase of the angiogram, especially in the rat of the ovariectomy group. The retinal vessel permeability of sham–ovariectomy group (17.8300±4.26569ng/mg) and normal control group (17.6113±4.57392ng/mg) are significantly lower than that of ovariectomy group (25.5030±4.37847ng/mg) that were detected by Evan’s Blue.
Conclusions: :
Ovariectomy can effectively establish the lower serum estrogen animal model to study the effects of estrogen. In experimental laser–induced rat retinal vein occlusion, the lower level of blood estrogen increased the retinal blood vessel permeability.
Keywords: retina • vascular occlusion/vascular occlusive disease