The Efficacy And Safety Of Adjuvant Intravitreal Injection Of Anti-Vascular Endothelial Growth Factors Prior To Vitrectomy In The Treatment Of Proliferative Diabetic Retinopathy:A Meta-analysis

Objective:To evaluate the safety and efficacy of the use of intravitreal injection of anti-VEGF drugs as a preoperative adjuvant therapy before vitrectomy for patients with proliferative diabetic retinopathy.Design:Meta-analysisMethods: A comprehensive search in EMbase?The Cochrane Library?Pubmed?CBM?Wan Fang Database?CNKI was conducted to identify potentially relevant randomized controlled trials published before January 2017 without any restriction on language.The Jadad Scale and the Cochrane Assessing Risk of Bias Tool are adopted to evaluate the methodological quality of the pooled trails.The software GRADEpro was used to evaluate the evidence based medicine quality.and publication bias was explored by searching for asymmetry in the funnel plot.Finally a meta-analysis of the pooled data was conducted by using the Rev Man 5.3 software.Results:A total of 923 eyes in 16 trials published from 2008 to 2016 were analyzed in this study.the enrolled eyes were divided into two groups:493 eyes in the vitrectomy with preoperative intravitreal injection of anti-VEGF drugs group(experimental group)and 430 eyes in the vitrectomy without preoperative intervention group(control group).The result of meta-analysis showed that the eyes in the experimental group achieved less intraoperative bleeding(OR=0.06,95%CI(0.02,0.15),P<0.00001)and shorter overall surgical time(WMD=-29.13,95%CI(-36.95,-21.30),P<0.00001)than the eyes in control group.The experimental group was also associated with less recurrent vitreous hemorrhage with in first 4 weeks(OR=0.29,95%CI(0.19,0.44),P<0.00001)and after 4 weeks(OR=0.34,95%CI(0.20,0.58),P<0.0001).Besides,there is also significant differneces between the two group in the occurance rate of iatrogenic retinal break,which was more likely with the control group(OR=0.24,95%CI(0.14,0.40),P < 0.00001).However,meta-analysis revealed no statistically differences in the best-corrected visual acuity between two groups(WMD=-0.51 log MAR,95%CI(-1.10,0.08),P=0.09).No incidence of obviously ocular or nonocular adverse event was reported by the pooled trails.Conclusions:The adjuvant intravitreal injection of anti-VEGF drugs prior to vitrectomy in proliferative diabetic retinopathy patients is a safe and efficient intervention.It significantly diminished the intraoperative and postoperative vision threatening complications and improved the overall treatment effect for the patients.Further trails are needed to explore the detailed therapy and the optimal dosage of the drugs.