Retinal arteriovenous shunt at the arteriovenous crossing

OBJECTIVE: The purpose of the study was to demonstrate that the arteriovenous shunt at the arteriovenous crossing could occur in major retinal vascular diseases other than Takayasu disease. DESIGN: Clinical review of consecutive case series. PARTICIPANTS: The authors studied 1885 eyes with retinal vascular diseases such as diabetic retinopathy, branch retinal vein occlusion, central retinal vein occlusion, central retinal artery occlusion, Leber's miliary aneurysms, Eales disease, Beh?et disease, and systemic lupus erythematosus retinopathy. INTERVENTION: Fluorescein fundus angiography using a wide-field fundus camera (60 degrees) was performed. MAIN OUTCOME MEASURES: Dye transit from artery to vein through sequential angiography. RESULTS: The arteriovenous shunt at the arteriovenous crossing was found in 8 eyes with proliferative diabetic retinopathy, 27 eyes with branch retinal vein occlusion in the chronic stage, 2 eyes with central retinal vein occlusion, 2 eyes with central retinal artery occlusion, and 2 eyes with miliary aneurysms. The arteriovenous shunt was formed by a direct inflow from artery to vein, showing vasodilation and hyperpermeability, followed by obliteration peripheral to the shunts. The pattern of initial inflow was classified into axial flow and laminar flow, and the inflow became wider and more rapid in the advanced stage. CONCLUSIONS: These findings indicate that the arteriovenous shunt at the arteriovenous crossing is not a unique phenomenon in Takayasu disease but rather is a basic pattern of retinal vascular reaction pathologic states.