A systematic review and meta-analysis of clinical outcomes of vitrectomy with or without intravitreal bevacizumab pretreatment for severe diabetic retinopathy

Abstract

Aims: To examine possible benefits of intravitreal bevacizumab (IVB) pretreatment in vitrectomy for severe diabetic retinopathy.

Methods: A comprehensive literature search was performed using the Cochrane Collaboration methodology to identify randomised controlled trials and comparative studies of vitrectomy with or without IVB pretreatment for severe or complicated diabetic retinopathy. Meta-analyses were performed for intraoperative (including intraoperative bleeding, endodiathermy, iatrogenic retinal tears and mean surgical time) and postoperative outcome parameters (including best-corrected visual acuity, recurrent vitreous haemorrhage, reabsorption time of blood and other complications).

Results: Six randomised controlled trials and one comparative study were identified and used for comparing vitrectomy alone (142 eyes, control group) with vitrectomy with IVB pretreatment (139 eyes). The intraoperative findings showed that the incidence of intraoperative bleeding and frequency of endodiathermy were statistically significantly less in the IVB pretreatment group (p<0.01) than in the vitrectomy alone group. The IVB pretreatment group took significantly less surgical time than the control group (p=0.003). Postoperative results indicated that reabsorption time of blood was significantly shorter (p=0.04), incidence of recurrent VH was almost significantly less (p=0.05), and final best-corrected visual acuity was significantly better (p=0.003) in the IVB group than in the control group. Other complications, including final retinal detachment, and reoperation, were statistically insignificant.

Conclusion: IVB pretreatment in vitrectomy can achieve excellent clinical outcomes for severe diabetic retinopathy. It potentially facilitates surgeons' manoeuvres and reduces intra- and postoperative complications.

Figure 1

Forest plots of OR of proportions of intraoperative bleeding (A), frequency of endodiathermy (B), iatrogenic retinal tears (C) during vitrectomy and forest plot of WMD of mean surgical time (D) comparing vitrectomy alone to vitrectomy with intravitreal bevacizumab (IVB) pretreatment. PPV, pars plana vitrectomy; WMD, weighted mean difference.

Figure 2

Forest plots of weighted mean difference (WMD) of reabsorption time of blood (A), OR of proportions of recurrent vitreous haemorrhage (B) and WMD of final mean BCVA (C) after surgery comparing vitrectomy alone to vitrectomy with intravitreal bevacizumab (IVB) pretreatment. PPV, pars plana vitrectomy.

Figure 3

Funnel plot of randomised controlled trials.