Reversal of blood flow in experimental branch retinal vein occlusion

. BACKGROUND AND OBJECTIVE: To demonstrate that the obstructed vascular lumen of the experimentally induced branch retinal vein occlusion (BRVO) induces retrograde blood flow, resulting in flow from the occluded vein to the feeder arterioles. . MATERIALS AND METHODS: Photocoagulation was used to create occlusion of the branch retinal vein in a monkey model (n = 2; 1 cynomolgus, 1 rhesus). Twenty-four hours following photocoagulation, the eyes were examined for evidence of vascular occlusive disease. Vascular occlusion was proven by fluorescent vesicle angiography with scanning laser ophthalmoscopy ; these results were recorded to SVHS videotape. The images were then serially analyzed frame by frame to track individual microsphere movement. . RESULTS: The authors observed retrograde flow proximal to the point of vessel obstruction and extending backward into the arterial system. . CONCLUSIONS: This demonstrates the existence of retrograde flow in an experimental model of BRVO and might explain vascular complications seen in this disease process.