Methodological quality of the review: High confidence

Author: Zhou, M, Wang, W, Huang, W, Zhang, X

Geographical coverage: Not reported

Sector: Glaucoma

Sub-sector: Surgical treatment for glaucoma

Equity focus: Not applicable

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Glaucoma is a major eye disease that may lead to blindness. Currently, trabeculectomy (Trab) is considered an effective surgical procedure to treat uncontrolled glaucoma. It has been used for more than 40 years, but available evidence for the assessment of efficacy and complications are not sufficient.

Objectives: To compare the efficacy and tolerability of trabeculectomies (Trabs) performed with and without releasable sutures in the treatment of patients with uncontrolled glaucoma.

Main findings: Six studies were included in this meta-analysis. Results indicated that the weighted mean difference of the intra-ocular pressure (IOP) reduction percentage from baseline was −4.56 when Trabs without releasable sutures were compared with Trabs with releasable sutures.

Trabs with releasable sutures were associated with numerically greater, but non-significant, efficacy in terms of lowered IOP compared with Trabs without releasable sutures. Trabs without releasable sutures were associated with a significantly higher frequency of hypotony and flat anterior chambers than Trabs with releasable sutures, with pooled relative risks of 4.04 and 2.57, respectively.

Overall, authors concluded that the efficacy of Trabs with releasable sutures was equivalent to Trabs without releasable sutures in controlling the IOP. It is also safer than a Trab without releasable sutures.

Authors noted that further research is needed to determine the validity, reliability and sensitivity using IOP as an outcome measure. Future studies should also focus on cataract grading following Trabs performed with and without releasable sutures.

Methodology: PUBMED, ISI Web of Science, EMBASE and the Cochrane Library were searched using the following terms: glaucoma or trabeculectomy or filtration surgery or filtering surgery or filtration operation or filtering operation AND suture. In addition, Google search and a manual search of the reference lists of the original reports and the review articles were retrieved through the electronic searches to identify studies.

There were no restrictions regarding publication year or language. The following inclusion criteria were used:

(a) Study type: RCT

(b) Population: glaucoma patients

(c) Intervention: trabeculectomies performed with releasable sutures versus trabeculectomy without releasable sutures, with or without the use of anti-metabolites

(d) Outcome variables: at least one of the outcomes of interest was included

(e) Follow-up time: ≥6 months

The data was extracted independently by two reviewers. Discrepancies between the two independent data extractions were resolved by discussion

For statistical analysis, the outcome measure was assessed on an intent-to-treat basis, and a random effect model was used. The weighted mean difference of continuous variables and the risk ratio of dichotomous variables were measured

Applicability/external validity: Authors did not discuss applicability/external validity of the findings of the review.

Geographic focus: There was no restriction to specific countries. Some low and middle-income countries were included.

Summary of quality assessment: This review was based on comprehensive searches of the literature. Methods used to screen studies for inclusion and extract data were appropriately conducted, thus minimising bias. Overall, there was high confidence in the conclusions about the effects of this study as minor limitations were identified.