Reintervention rate in glaucoma filtering surgery: A systematic review and meta-analysis

Author: Marolo P, Reibaldi M, Fallico M, Maugeri A, Barchitta M, Agodi A, Parisi G, Caselgrandi P, Ventre L, Ahmed IIK.

Geographical coverage: Not reported

Sector: Glaucoma

Sub-sector: Treatment

Equity focus: Not reported

Study population: Patients with glaucoma

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background

Glaucoma is a leading cause of visual impairment and blindness. Managing intraocular pressure (IOP) is the primary treatment goal, often requiring surgical intervention. Despite advancements in surgical techniques, trabeculectomy remains the most commonly performed glaucoma filtering procedure. A key challenge in these surgeries is the need for reintervention, which increases patient risk, surgical complexity, and healthcare costs. While some studies use reintervention rates within 90 days post-surgery as a quality measure, this timeframe may overlook long-term complications and IOP control.

Objectives

To assess the reintervention rate following glaucoma filtering surgery.

Main findings

All types of glaucoma filtering surgeries showed comparable overall reintervention rates. However, Baerveldt and Preserflo Microshunt procedures exhibited lower reintervention rates, while the Xen procedure had a higher rate relative to the overall average.

Out of 10,457 records screened, 93 studies involving 8,345 eyes were included. All studies were prospective; 51 were randomised and 42 non-randomised.

The total reintervention rate was 1.84 (95% confidence interval [CI]: 1.57 to 2.13). Lower reintervention rates were observed with the Baerveldt implant (0.53, 95% CI: 0.29 to 0.83) and the Preserflo Microshunt (0.60, 95% CI: 0.15 to 1.29), while a higher rate was reported for the Xen procedure (4.26, 95% CI: 2.59 to 6.31).

Subcategory results included: manipulation rate – 0.99 (95% CI: 0.77 to 1.23); in-clinic reintervention rate – 0.08 (95% CI: 0.05 to 0.12); and in-operating room reintervention rate – 0.28 (95% CI: 0.22 to 0.35). The reintervention rate for IOP control was 1.26 (95% CI: 1.04 to 1.51), while for complications it was 0.27 (95% CI: 0.21 to 0.35).

Subgroup analyses revealed that studies with 12-month follow-up had higher reintervention rates compared to those with over 24 months of follow-up.

Methodology

Searches were conducted in January 2021 in PubMed, Medline, and Embase to identify prospective studies that reported reintervention rates following glaucoma filtering surgery with at least 12 months of follow-up.

Two investigators independently searched and screened studies. Reference lists from included studies and relevant reviews were also examined. Authors were contacted for clarifications or additional information when necessary. Two reviewers independently extracted data and assessed the quality of the studies using the Cochrane Handbook for RCTs and the Methodological Index for Non-Randomised Studies (MINORS) for non-randomised studies. Discrepancies were resolved through discussion or consultation with a third reviewer.

Data were synthesised using a random-effects meta-analysis. Subgroup analyses were conducted to evaluate differences by demographic, clinical, and surgical variables. Heterogeneity was assessed using Q statistics and the I² index. Publication bias was assessed using funnel plots.

Applicability / External validity

The review offered limited discussion on applicability. It noted that only one study on the Preserflo Microshunt, covering 23 eyes, was included. The small sample size restricts the generalisability of findings and limits the ability to draw firm conclusions. Larger, more comprehensive studies are needed to support wider applicability across diverse populations and clinical settings.

Geographic focus

The geographic location of the included studies was not reported.

Summary of quality assessment

Confidence in the conclusions is medium. The authors did not include grey literature in the search strategy, nor did they analyse or report results according to risk of bias in the included studies.