Objective To evaluate the effect of releasable sutures on shallow anterior chamber, filtering bleb and long-term intraocular pressure (IOP). Methods We searched MEDLINE (1971 to 2007), OVID (1971 to 2007) and National Science and Technology Library (1971 to 2007). Randomized controlled trials (RCTs) of the effect of releasable sutures on trabeculectomy were collected. Study selection and assessment, data collection and analyses were undertaken and cross-checked by two reviewers. Meta-analyses were performed with The Cochrane Collaboration’s RevMan 4.2.10 software. Results Six RCTs involving 341 eyes were included. Significant differences were observed in the reduction of postoperative shallow anterior chamber (RD –0.23, 95%CI –0.31 to –0.14, Plt;0.000 01) and functional filtering blebs (RD –0.15, 95%CI –0.27 to –0.02, P=0.02). But, no differences were observed for the control of long-term IOP (SMD –0.13, 95%CI –0.37 to 0.10, P=0.27). Conclusion The evidence currently available showed that releasable sutures could reduce the incidence of shallow anterior chamber and has no beneficial effect in controlling long-term IOP. The current evidence is insufficient to define the efficacy of maintaining functional filtering blebs. Further large-scale, high-quality randomized controlled trials are needed.