Micropuncture for treatment of experimental retinal vein occlusion

Objective: To develop a method for treatment of retinal vein occlusion by infusing thrombolytic agents into the retinal vein with micropuncture of the retinal vein.Materials:Twenty four miniature pigs of experimental retinal vein occlusion were divided into three groups: （1） non operation, （2） sterile water was infused into obstructed retinal vein, （3） tissue type plasminogen activator was infused into obstructed retinal vein. Methods: we designed an ultramicrosurgical system that used the control of a six degree of freedom micromanipulator and an electromagnetic holder to direct a micropipette tip to puncture retinal vein Low dose tissue type plasminogen activator or sterile water was then infused into the retinal vein via a controlled microperfusion pump to treat experimental retinal vein occlusion Fluorescein angiographies and histological sections were taken to correlate the morphological alterations with clinical observations. Results:The thrombus was lysed by tissue type plasminogen activator and then dropped following the blood flow After micropipette was drawn out from the vessel, no bleeding and no leakage of the infused drug was found from the site of puncture But sterile water could not flush the clot away When the thrombus did not drop and the infusion liquid flow back to the distal retinal vein for a long time, exudative retinal detachment would happen. Conclusion: This study shows that it may be a new technique to infuse thrombolytic agents into retinal vein for treatment of retinal vein occlusion.