Anti‐vascular endothelial growth factor for prevention of postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy
Abstract
Background
Postoperative vitreous cavity haemorrhage (POVCH) is a significant complication following vitrectomy for proliferative diabetic retinopathy (PDR). It delays visual recovery and can make further treatment difficult if the view of the fundus is significantly obscured. A number of interventions to reduce the incidence of POVCH have been proposed, including the perioperative use of anti‐vascular endothelial growth factor (anti‐VEGF). Anti‐VEGFs reduce vascular proliferation and the vascularity of neovascular tissue, which is often the source of bleeding following vitrectomy.
Objectives
The review aims to assess the effect of perioperative anti‐VEGF in reducing the incidence of POVCH.
Search methods
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 2), MEDLINE (January 1950 to March 2011), PubMed (10 March 2011), EMBASE (January 1980 to March 2011), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled‐trials.com) and ClinicalTrials.gov (www.clinicaltrial.gov). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 10 March 2011.
Selection criteria
We included all randomised controlled trials (RCTs) that looked at the use of anti‐VEGFs and the incidence of POVCH in people undergoing vitrectomy for PDR.
Data collection and analysis
Both review authors independently assessed and extracted the data using a standardised form based on the CONSORT statement.
Main results
We included four studies (202 eyes of 198 participants) in this review. The four RCTs met the inclusion criteria, but we were unable to conduct a meta‐analysis due to methodological issues in three of the trials. We have provided a summary of the effects of the interventions. We have also provided a summary of the current literature addressing each primary and secondary outcome.
Authors' conclusions
Results from one of the included studies support the use of preoperative intravitreal bevacizumab to reduce the incidence of early POVCH. There are currently no other high quality RCTs that support the use of anti‐VEGF agents perioperatively to reduce the incidence of early or late POVCH. The remaining studies identified by the search suggest that the preoperative use of bevacizumab may reduce the incidence of early POVCH, but it should be recognised that there are a number of significant methodological issues in these studies that lead us to be cautious when interpreting their findings and make any definitive conclusions unwarranted.
PICOs
Plain language summary
Anti‐vascular endothelial growth factor for prevention of postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy
Postoperative vitreous cavity haemorrhage (POVCH) is a significant complication following vitrectomy (removal of the vitreous gel from the posterior chamber of the eye) for the treatment of proliferative retinopathy (the growth of abnormal blood vessels from the retina which is a layer of tissue at the back of the eye), occurring in approximately 30% of cases. It has two main forms, 'early' when haemorrhage (bleeding) is present in the first few postoperative days and 'late', when haemorrhage occurs a number of months after surgery. The presence of POVCH delays visual recovery, can lead to elevated pressure within the eye and can make further treatment for diabetic retinopathy difficult. Revision surgery is required in 10% of patients, which has significant implications for resources, time and cost. The use of anti‐vascular endothelial growth factor (anti‐VEGF) before surgery (preoperatively) has been proposed as an intervention to reduce the incidence of POVCH.
The electronic database searches identified four randomised controlled trials (RCTs) and six prospective non‐randomised trials. The four RCTs met the inclusion criteria, but we were not able to conduct a meta‐analysis (combining the data from the trials) due to methodological issues within three of the trials. In light of this, we have provided a summary of the current available evidence. A summary of the identified studies suggests that bevacizumab (which acts to block the action of VEGF) may reduce the incidence of early postoperative haemorrhage, but has little effect on the incidence of late haemorrhage.
The risk of adverse events when using preoperative anti‐VEGF appears small.
Although there is currently only limited high‐quality evidence available, the preoperative use of anti‐VEGF in diabetic vitrectomy may reduce the incidence of early POVCH. There are currently no RCTs which comment on the effect of anti‐VEGF given before or during surgery on late POVCH.
