Surgical interventions for primary congenital glaucoma

Methodological quality of the review: High confidence

Authors: Ghate D, Wang X.

Region: USA, Egypt, Israel, Lebanon and Saudi Arabia

Sector: Glaucoma

Sub-sector: Sugery

Equity focus: Children aged 1 or less

Review type: Other review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background:

Primary congenital glaucoma (PCG) manifests within the first few years of a child’s life and is not associated with any other systemic or ocular abnormalities. PCG results in considerable morbidity even in developed countries. Several surgical techniques for treating this condition, and lowering the intraocular pressure (IOP) associated with it, have been described.

Objectives:

To compare the effectiveness and safety of different surgical techniques for PCG.

Main findings:

The authors included a total of six trials (four randomized and two quasi-randomized) with 102 eyes in 61 children. Two trials were conducted in the USA and one trial each in Egypt, Israel, Lebanon and Saudi Arabia. All trials included children aged younger than one year when diagnosed with PCG, and followed them for periods ranging from six months to five years. No two trials compared the same pair of surgical interventions, so the authors did not perform any meta-analysis.

One trial compared trabeculotomy versus goniotomy; a second trial compared combined trabeculectomy-trabeculotomy with mitomycin C versus trabeculectomy-trabeculotomy with mitomycin C and deep sclerectomy; a third trial compared combined trabeculotomy-trabeculectomy versus trabeculotomy; a fourth trial compared one goniotomy versus two goniotomies; a fifth trial compared trabeculotomy versus viscocanalostomy; and the sixth trial compared surgical goniotomy versus neodymium-YAG laser goniotomy.

For IOP change and surgical success (defined by IOP achieved), none of the trials reported a difference between pairs of surgical techniques. However, the authors note that due to the limited sample sizes for all trials (average of 10 children per trial), the evidence as to whether a particular surgical technique is effective and which surgical technique is better still remains uncertain. Adverse events, such as choroidal detachment, shallow anterior chamber and hyphema, were reported from four trials. The authors found that none of the trials reported quality of life or economic data. These trials were neither designed nor reported well overall. Two trials were quasi-randomized trials and judged to have high risk of selection bias; four trials were at unclear or high risk for performance bias and detection bias; and we judged one trial to have high risk of attrition bias due to high proportions of losses to follow-up.

Reviewers stated that due to poor study design and reporting, the reliability and applicability of evidence remain unclear.

Methodology: 

The authors searched CENTRAL, Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, EMBASE, PubMed, the metaRegister of Controlled Trials (mRCT), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, from inception to 2014. No date or language restrictions were applied in the electronic searches for trials. In addition, the authors reviewed references lists of the trials included in the review.

Inclusion criteria consisted of randomized and quasi-randomized trials in which different types of surgical interventions were compared in children under five years of age with PCG. Primary outcome measure for comparison of interventions was IOP at one year after surgery.

Two reviewers independently reviewed studies for inclusion, extracted data of included studies and assessed risk of bias in included studies.

The authors conducted a narrative synthesis of included studies.

Applicability/external validity:

Reviewers stated that due to poor study design and reporting, the reliability and applicability of evidence remain unclear.

Geographic focus

Included studies were conducted in the USA, Egypt, Israel, Lebanon and Saudi Arabia. However, the authors reported that due to poor quality of included studies it is not possible to discuss applicability of findings to other settings.

Summary of quality assessment:

Overall, there is high confidence in the review as one minor limitation was identified. Authors did not contact experts/authors for further relevant studies.