Treatment of retinal vein occlusion in rabbits with traditional Chinese medicine Fufang XueShuan Tong

Background Retinal vein occlusion （RVO） is one of the most common causes of visual loss. Many approaches have been tried to treat central retinal vein occlusion （CRVO）, and branch retinal vein occlusion （BRVO） with various results. However, there is no defined protocol and limited evidence to support the interventions currently used. The aim of this study was to assess the efficacy of the traditional Chinese medicine Fufang XueShuan Tong （FXST） in treating experimentally created RVO. Methods RVO model was first induced in forty-four pigmented rabbits through photocoagulation following injection of rose Bengal. The rabbits were divided into four groups based on the dose of FXST administered （212 mg/kg, 424 mg/kg, 848 mg/kg and control group）. The rabbits were observed for four weeks after the procedure, using color fundus photography, fundus fluorescein angiography and electroretinogram examination. Vascular endothelial growth factor （VEGF）, interleukin-6 and nitric oxide （NO） levels in the vitreous and histopathologic evaluation were monitored. Results The obstructed vessels in the treatment groups reopened or anastomosed faster than those in the control group （P〈0.05）. The amplitude of maximum b wave and the oscillatory potential were significantly higher in the treatment groups than in the control group （P 〈0.01）. At both two weeks and four weeks, VEGF and IL-6 levels in the vitreous were significantly decreased in the treatment groups （P 〈0.01）, while NO levels were significantly elevated （P 〈0.01）. At the same time, histopathologic evaluation showed different retinal neuroepithelium structures in the different groups. Immunoreactivity of VEGF was greater in the control group than in the treatment groups. Conclusion FXST was helpful in reconstructing retinal vessels in the RVO model, protecting retinal structures and improvinq visual function, and could inhibit the neovascular factor.