Primary Objective: To investigate ranibizumab's benefit on prevention of early postoperative vitreous haemorrhage in PDR-DME patients receiving vitrectomy.~Secondary Objective:To investigate ranibizumab's additional benefit on visual improvement, facilitation of surgery and postoperative outcomes in PDR-DME patients receiving vitrectomy.~Study design: This study is a prospective, randomized, single-blinded, blank-controlled, multi-center clinical trial that requires vitrectomy for PDR-DME patients.
To investigate ranibizumab's benefit on prevention of early postoperative vitreous haemorrhage in PDR-DME patients receiving vitrectomy.