Retinal Infusion Injury In Intervention Fibrinolysis By Micropuncture Of Retinal Vein

Retinal infusion injury in intervention fibrinolysis by micropuncture of retina! veinRetinal vein occlusion is a common blinded illness. The clinical effects of systemic and local treatment had little effect. The effects on thromblysis depend on delivering of plasminogen activator and interactive mode within clot. Based on the increasing appliances of micromanpulator and development of micropuncture of retinal vein. Fibrinolytic therapy is accelerated by increasing penetration of activator into the clot to increase the area of active fibrinolysis. To investigate the effects of infusing of retinal vein on retina and vessels, the study followed.Purpose: To investigate the changes of retinal tissue and vessels when solutions (with or without thrombolytic agents) were directly infused into retinal obstructed vein in different velocity and time in experimental retinal vein occlusion.Methods: The miniature pigs underwent unilateral retinal vein thrombosis with the use of a combination of intravenously administered rose bengal and light illumination of the vein and randomly fall into two groups. Control group (n=3) was observed without further intervention. In experimental group, balancedsalt solution (n=12) or balanced salt solution + tissue plasminogen activator(n=60) were respectively infused into retinal obstructed vein at different velocity (30s 60> 80ml/h) and different time of 1(K 20 minutes. Retina was evaluated by fundus photographs and histopathology.Results: The retinal changes showed no significant differences between control group and experimental group with infusion at the rate of 30 and 60ml/h for 10-20min. The exudative retinal detachment occurred at 80ml/h for 20 minutes in all solutions. Retinal histopathology and transmit electron microscope showed that endothelial cell conjunction of retinal vein and capillary were injured. But no exudative retinal detachment appeared when balanced salt solution or balanced salt solution + tissue plasminogen activator was infused at the rate of 30 and 60 ml/h for 20 min. Clot lysis occurred in 2/10, 6/10, and 7/10 pigs respectively following the 30, 60, and 80ml/h tPA infusion for 20 minutes. Conclusions: Infusion of 60ml/h for 20 minutes may be optimal way for tissue plasminogen activator lysing thrombus in retinal vein.