BACKGROUND: This study aimed to evaluate the effect of pre-operative versus pre-operative plus post-operative intravitreal conbercept (IVC) injection on severe proliferative diabetic retinopathy (PDR).
METHODS: This was a prospective, comparative and randomised study. A total of 84 patients who underwent vitrectomy for severe PDR were included in this study. Patients were randomly divided into control (41 eyes) and experiment (43 eyes) groups. Patients in the experiment group received adjunctive pre-operative and post-operative IVC injection, whereas patients in the control group only received pre-operative IVC injection. The incidence of post-operative vitreous haemorrhage (POVH), best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were determined.
RESULTS: The incidence of early POVH was significantly different between the two groups, but no significant difference was observed between groups at 3 and 6 months. In the experiment group, the BCVA was significantly improved 1 month after surgery when compared with the control group (p 0.019). There was no marked difference in the mean post-operative BCVA at 3 and 6 months between groups (p 0.063 and 0.082). CRT was significantly lower in the experiment group than in the control group at 1 and 3 months after surgery (p 0.037 and 0.041), but there was no significant difference at 6 months (p 0.894).
CONCLUSIONS: Additional IVC injected at the end of surgery improves the POVH and BCVA at the early stage after surgery in severe PDR, but this benefit is absent at 6 months. Further studies are needed to investigate the effect of IVC at the end of vitrectomy.
BACKGROUND: chictr.org.cn identifier: ChiCTR2200060735. Retrospectively registered, register date: 9 June 2022.

OBJECTIVE: To compare prospectively intravitreal ranibizumab treatment and pars plana vitrectomy (PPV) in patients with recurrent vitreous haemorrhage (VH) due to proliferative diabetic retinopathy (PDR), who were previously treated with PPV.
METHODS: Participants in this prospective study were 37 patients (37 eyes) with PDR, previously treated with PPV. All patients presented recurrent VH and were treated with either ranibizumab (n = 18) or PPV (n = 19). All participants were examined at week 2 post-treatment and every month thereafter for 1 year. Main outcomes were the need of PPV, the rate of recurrence of VH and the change in visual acuity by the end of the 12-month follow-up.
RESULTS: At month 12, there was statistically significant improvement in visual acuity in both groups compared to baseline, but the two groups did not differ regarding the change in visual acuity. In ranibizumab group, two patients presented recurrent VH during the follow-up and one patient needed PPV to clear the VH by month 12. In PPV group, two patients had mild recurrent VH, which cleared itself. No statistically significant difference was noticed regarding the rate of recurrent VH and the need of PPV between the two groups.
CONCLUSIONS: Intravitreal ranibizumab seems to be a safe and effective treatment alternative in patients with recurrent VH secondary to PDR, who had been previously treated with PPV.