Comparison of Phaco-Trabeculectomy and MSICS-Trab in Cataract and Glaucoma Patients

Background and Rationale Cataract and glaucoma are two of the leading causes of preventable blindness globally, presenting significant public health challenges, particularly in resource-limited settings such as Nigeria. The coexistence of cataract and glaucoma complicates surgical management, as cataract surgery alone may improve visual acuity but is insufficient to achieve long-term control of intraocular pressure (IOP) in glaucoma patients.

Combined surgical procedures, such as Phaco-Trabeculectomy and Manual Small Incision Cataract Surgery (MSICS) with Trabeculectomy, have been adopted to address these dual ocular conditions in a single intervention. However, evidence comparing the efficacy, safety, and long-term outcomes of these two approaches remains limited, particularly in Sub-Saharan Africa. This study seeks to bridge this critical gap in clinical evidence by generating region-specific data to optimize surgical decision-making for patients with coexisting cataract and glaucoma.

ECWA Eye Hospital, Kano, a tertiary eye care center in Nigeria renowned for its excellence in ophthalmology, provides the ideal setting for conducting this interventional study.

Study Objectives

This study aims to:

Determine whether Phaco-Trabeculectomy or MSICS-Trabeculectomy offers superior intraocular pressure (IOP) control in patients with coexisting cataract and glaucoma.

Compare the visual acuity outcomes between the two surgical techniques. Evaluate and compare the incidence of postoperative complications, such as bleb failure, hypotony, and infection.

Assess patient satisfaction and quality of life using validated questionnaires.

Study Design

This is a randomized, parallel-group, interventional study conducted over a 12-month follow-up period. Eligible participants are randomized into two arms using a block randomization approach to ensure balanced allocation:

Phaco-Trabeculectomy Group MSICS-Trabeculectomy Group Randomization minimizes selection bias and ensures comparability of baseline characteristics between groups.

Key Surgical Interventions Phaco-Trabeculectomy This procedure integrates phacoemulsification, a modern cataract extraction technique, with trabeculectomy to achieve IOP control.

A 3.2 mm corneal incision is made for ultrasonic emulsification and aspiration of the cataract.

A trabeculectomy is performed to create a filtration bleb, facilitating aqueous humor drainage.

This method is precise, minimally invasive, and well-suited for modern ophthalmic practice.

MSICS-Trabeculectomy This procedure combines manual extracapsular cataract extraction with trabeculectomy and is particularly advantageous in resource-limited settings.

A fornix-based conjunctival flap is raised, and a larger manual incision is made to remove the cataract nucleus.

Trabeculectomy is performed using the same technique as in the Phaco-Trabeculectomy group.

The MSICS-Trabeculectomy approach is practical, cost-effective, and suitable for environments where phacoemulsification equipment is unavailable.

Postoperative Management

Standardized postoperative care includes:

Administration of topical corticosteroids, antibiotics, and anti-glaucoma medications to reduce inflammation, prevent infection, and manage IOP.

Follow-up visits conducted on day 1, week 1, months 1, 3, 6, and 12 to assess clinical outcomes and monitor for complications, including hypotony, bleb failure, and infection.

Bleb morphology is evaluated using validated grading systems, while patient satisfaction and quality of life are assessed using standardized questionnaires.

Data Collection and Analysis

Data on surgical outcomes, including IOP, visual acuity, and postoperative complications, are systematically collected at predefined intervals. Statistical tools are employed for comparative analysis:

Continuous variables such as IOP and visual acuity are analyzed using paired and unpaired t-tests.

Categorical variables, including complication rates, are analyzed using chi-square tests and logistic regression models.

Results will be presented as mean ± standard deviation for continuous variables and as percentages for categorical variables.

Significance of the Study

This study provides a direct comparative analysis of Phaco-Trabeculectomy and MSICS-Trabeculectomy in a Sub-Saharan African context. By evaluating clinical efficacy, cost-effectiveness, and patient-reported outcomes, the findings will:

Inform clinical practice by identifying the optimal surgical approach for managing coexisting cataract and glaucoma.

Address regional gaps in evidence-based ophthalmic care, particularly in resource-limited settings.

Serve as a foundation for further studies exploring long-term surgical outcomes and innovations in glaucoma-cataract management.

Novel Contributions

This study is one of the first to comprehensively evaluate two combined surgical techniques in a Sub-Saharan African population. Its strengths include:

Rigorous randomization to ensure unbiased comparisons. Systematic data collection at predefined intervals over 12 months. Use of validated tools for assessing bleb morphology, complications, and patient satisfaction.

By bridging the gap in clinical evidence, this study has the potential to improve surgical decision-making, enhance patient outcomes, and guide ophthalmic care strategies in resource-constrained settings.

Conclusion This interventional study will provide critical insights into the comparative effectiveness and safety of Phaco-Trabeculectomy and MSICS-Trabeculectomy for managing coexisting cataract and glaucoma. Its findings are expected to have significant implications for ophthalmic practice in Nigeria and other resource-limited regions, ultimately contributing to the prevention of avoidable blindness.

Inclusion criteria

• Adult patients aged ≥18 years.
• Patients diagnosed with coexisting cataracts and primary open-angle glaucoma.
• Patients who have provided informed consent to participate in the study.

Exclusion criteria

• Patients with angle-closure glaucoma.
• Patients with secondary glaucoma or glaucoma-associated ocular or systemic anomalies.
• Patients with a history of ocular surgeries, such as trabeculectomy, cataract surgery, or other glaucoma surgeries.
• Patients with corneal or anterior segment diseases that could impede detailed examination (e.g., scleritis, bullous keratopathy, corneal scarring, corneal degenerations, or uveitis).
• Patients with posterior segment diseases affecting visual interpretation (e.g., diabetic retinopathy, hypertensive retinopathy, high axial myopia, retinal detachment, vitreous hemorrhage, macular degeneration, central retinal vein occlusion, or sickle cell retinopathy).
• Patients unwilling to provide voluntary informed consent or those who chose to withdraw from the study at any point.
• Patients with only one functional eye.