Manual Small Incision Cataract Surgery Combined with Trabeculectomy Versus Phacoemulsification Combined with Trabeculectomy for Coexisting Glaucoma and Cataract: A Systematic Review and Meta-Analysis

Author: Amaral, D. C., Guedes, J., de Oliveira Caneca, K., Pereira, S. F., Alves, M. R., Manso, J. E. F., Monteiro, M. L. R., Louzada, R. N.

Geographical coverage: India

Sector: Cataract and glaucoma

Sub–sector: Treatment safety and efficacy

Equity focus: Not reported

Study population: Patients with cataract and glaucoma

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Cataract and glaucoma account for most cases of vision impairment or loss worldwide and often coexist in older people. Both can be prevented with early detection and timely intervention. Manual small‑incision cataract surgery (MSICS) offers a viable, cost‑effective option with favourable outcomes. When combined with trabeculectomy, it can improve management of cataract associated with glaucoma. However, the procedure takes longer and carries risks associated with both cataract surgery and trabeculectomy. Phacoemulsification, like MSICS, has several advantages over other cataract techniques and has shown comparable intra‑operative and post‑operative complication rates.

Objective: To evaluate the efficacy and safety of MSICS combined with trabeculectomy (MSICS‑trab) compared with phacoemulsification combined with trabeculectomy (phaco‑trab) for the management of coexisting glaucoma and cataract.

Main findings: The review included five retrospective studies involving 568 eyes, all conducted in India. Four studies had moderate risk of bias and one had serious risk due to misclassification of interventions (ROBINS‑I). Meta‑analysis showed no significant difference between phaco‑trab and MSICS‑trab in intra‑ocular pressure reduction at one week (p = 0.72), one month (p = 0.33), 12 months (p = 0.40) or at the last reported visit (p = 0.69). Across the pooled studies, 150 complications were recorded in 568 eyes. Rates of overall complications (p = 0.36), serious complications (p = 0.50), zonular dialysis (p = 0.68), Descemet’s detachment (p = 0.89), hyphaema (p = 0.82), fibrin reaction (p = 0.35) and hypotony (p = 0.99) did not differ significantly between groups.

Methodology:  Searches were conducted in PubMed, Web of Science, Embase and the Cochrane Library from inception to January 2024 without language restrictions. Randomised controlled trials and non‑randomised studies involving patients aged ≥ 18 years with any type of glaucoma and cataract were eligible if they had at least one week of follow‑up and reported relevant clinical outcomes. Animal studies, case reports and studies with overlapping populations were excluded. Reference lists of included studies were screened manually for additional citations.

Two reviewers independently screened titles, abstracts and full texts, extracted data and appraised study quality; disagreements were resolved by discussion. Risk of bias was assessed with ROBINS‑I. Random‑effects meta‑analysis was performed; heterogeneity was quantified with the Cochrane Q test and I² statistic.

Applicability/external validity: Reliance on retrospective studies and limited long‑term data restrict the strength and generalisability of the findings. Because all included studies were conducted in India, caution is needed when applying the results to other settings. Large, randomised, long‑term studies in diverse populations are required.

Geographic focus: No geographical limits were applied, but all included studies were from India.

Summary of quality assessment: Overall confidence in the evidence is medium. Searches were comprehensive; inclusion criteria were clear; dual independent screening, extraction and quality appraisal were performed; and meta‑analysis methods were appropriate. However, the review did not provide a list of excluded studies, and findings were not stratified by risk of bias.