·AIM:To compare clinical outcomes of complex trabeculectomy combined with or without human umbilical vein(HUV)transplantation in refractory glaucoma.METHODS:This clinical trials included 28 eyes with refractory glaucoma at high risks as vascularization,uveitis,aphakia,pseudophakic and young ages.Complex trabeculectomy with HUV transplantation under the scleral flap was performed in 15 eyes and complex trabeculectomy without HUV transplantation in 13 eyes.The outcome measured including surgical success rate,postoperative intraocular pressure(IOP),the number of antiglaucoma medications and complications.All patients were followed for 12 months.RESULTS:Complete success was seen in 12/15(80.0%)study eyes and 8/13(61.5%)control eyes at 6 months postoperatively,and in 11/15(73.3%)and 6/13(46.2%)at 12 months after surgery,respectively.IOP decreased from 50.9±12.2mmHg and 49.7±11.7mmHg preoperatively in study and control groups to 17.3±1.1mmHg and 20.9±2.2mmHg,respectively at 12 months(P=0.00).Early postoperative hypotony developed in 2 control eyes owing to excessive filtration but none of study eyes.Encapsulated bleb occurred in 4 control eyes but in 1 study eye.CONCLUSION:In refractory glaucoma,complex trabeculectomy combined with HUV transplantation compared to without HUV transplantation has higher success rate,lower postoperatively mean IOP,and lower complication rate.