Macular laser photocoagulation with or without intravitreal triamcinolone pretreatment for diabetic macular edema: a result from five randomized controlled trials

AIM:To assess possible benefits of intravitreal triamcinolone acetonide(IVTA)injection as pretreatment for macular laser photocoagulation(MLP)in patients with diabetic macular edema(DME).·METHODS:Published randomized controlled trials(RCTs)concerning MLP with or without IVTA pretreatment for DME were retrieved from databases CNKI,Medline,EMbase,Web of Science,and the Cochrane Library.A Meta-analysis on eligible studies was conducted using Rev Man 5.0 software.Two investigators independently assessed the quality of the trials and extracted data.Main outcome measures included the change in best-corrected visual acuity(BCVA),difference in central macular thickness(CMT)and adverse events reporting in particular elevated intraocular pressure within the follow-up period.The results were pooled using weight mean difference(WMD)or odds risk(OR)with their corresponding 95%confidence intervals(CI).A fixed-or random-effect model was employed depending on the heterogeneity of the inclusion trials.·RESULTS:Finally,five independent RCTs were identified and used for comparing MLP with IVTA pretreatment(131 eyes)with MLP alone(133 eyes,control group).The overall study quality was relatively higher according to the modified Jadad scale.The Metaanalysis showed that MLP with IVTA pretreatment significantly reduced CMT at one,three and six months(P=0.002,0.0003 and 0.04,respectively),compared with MLP alone.The IVTA pretreatment group showed statistically significant improvements in BCVA at the one-month follow up as compared with the control group(P=0.03).At three-and six-month follow up,there was a beneficial trend towards improving visual acuity in the IVTA pretreatment group without statistical significance between groups(P=0.06 and 0.20,respectively).The incidence of elevation of intraocular pressure was significantly higher in the IVTA pretreatment group than in the control group(P<0.0001).No evidence of publication bias was present according to Begg’s test and Egger’s test.There was a low level of heterogeneity in the included studies.·CONCLUSION:This Meta-analysis indicates that MLP with IVTA pretreatment has a better therapeutic effect in terms of CMT reduction and earlier(1mo)visual improvement for patients with DME as compared with MLP alone.Further confirmation with rigorously welldesigned multi-center trials is needed.