Abstract： ?AIM: To observe the efficacy of intravitreal injection of conbercept in the treatment of late postoperative vitreous cavity haemorrhage ( POVCH ) in patients with proliferative diabetic retinopathy ( PDR) .?METHODS: A total of 56 patients ( 57 eyes ) with late POVCH after vitrectomy in patients with PDR were retrospectively analyzed. Among them, 28 eyes that received intravitreal injection of 0. 05 mL conbercept were selected as the conbercept group, whereas 29 eyes that did not receive intravitreal injection of conbercept were selected as the control group. Best corrected visual acuity ( BCVA ) , the degree of vitreous haemorrhage ( VH ) , intraocular pressure and ocular fundus were recorded before and after vitrectomy and injection, at 1mo after late POVCH and at the end of follow-up, respectively. Moreover, the number of eyes that received the secondary surgery ( vitreous lavage ) was compared and the patients' general conditions such as blood glucose, blood pressure and mental health were observed.?RESULTS: BCVA was better in the conbercept group than in the control group(1.26±0.13 vs.1.76±0.20;P=0.04) at 1mo after late POVCH.There was no difference in BCVA at POVCH onset and at the end of follow-up between the two groups (P=0.08, 0.24). In terms of VH opacity,there was significant improvement in 13 eyes, moderate improvement in 9 eyes and no improvement in 6 eyes in the conbercept group. However, in the control group, there was significant improvement in 11 eyes, moderate improvement in 3 eyes and no improvement in 15 eyes ( P= 0. 03 ) . Eyes in the conbercept group showed less possibility of reoperation than those in the control group (21％ vs. 51％,P=0.045). The mean times of injections in the conbercept group was 2. 24 ± 1. 16 ( range: 1-5 ) . The follow-up period ranged from 12 to 24mo,with an average of 16. 47 ± 3. 34mo. Among the 28 eyes with POVCH, 11 ( 19％) eyes had the fundus fibrous vascular membrane and 11 ( 19％) eyes had retinal neovessels. Neovascular glaucoma ( NVG ) and iris neovascularization were observed in 10 ( 18％) and 4 ( 7％) eyes, respectively. After the amelioration of haemorrhage of POVCH in 57 eyes, 44 ( 77％) eyes were supplemented with retinal photocoagulation. At POVCH onset, 43 ( 75％) patients exhibited abnormal blood glucose ( glycosylated hemoglobin ) and ( or ) blood pressure, and 6 ( 11％) patients were reported to felt tired or anger.?CONCLUSION: Intravitreal injection of conbercept for late POVCH in patients with PDR can promote the amelioration of haemorrhage, improve visual acuity, and reduce the need for reoperation. Moreover, strict control of systemic factors such as blood pressure, blood glucose and psychological situation is crucial in patients with PDR for late POVCH.