Ab-Externo MicroShunt versus Trabeculectomy in Primary Open-Angle Glaucoma: Two-Year Results from a Randomized,...

Area of Science:

• Ophthalmology
• Glaucoma Surgery
• Medical Devices

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness worldwide.
• Effective management of POAG often requires surgical intervention to lower intraocular pressure (IOP).
• The MicroShunt and trabeculectomy are surgical options for POAG, each with distinct mechanisms and outcomes.

Purpose of the Study:

• To compare the effectiveness and safety of the MicroShunt versus trabeculectomy in patients with POAG.
• Evaluate surgical success rates, IOP reduction, and medication use.
• Assess the incidence of adverse events and postoperative interventions for both procedures.

Main Methods:

• A prospective, randomized, multicenter trial was conducted in the US and Europe.
• Adult patients (40-85 years) with POAG inadequately controlled by medication were randomized 3:1 to MicroShunt (n=395) or trabeculectomy (n=132).
• Both procedures were augmented with mitomycin C (MMC), and surgical success was defined as a ≥20% reduction in diurnal IOP without increased medication.

Main Results:

• At 2 years, trabeculectomy achieved a higher surgical success rate (64.4%) compared to the MicroShunt (50.6%) (P=0.005).
• Both groups showed significant IOP reduction and decreased medication use from baseline (P<0.001).
• Hypotony was more frequent after trabeculectomy (51.1%) than MicroShunt (30.9%) (P<0.001), while MicroShunt required repositioning/explantation in 6.8% of cases.

Conclusions:

• Both MicroShunt and trabeculectomy are effective in reducing IOP and medication use in POAG patients.
• Trabeculectomy demonstrated superior surgical success rates at the two-year follow-up.
• While both procedures have associated risks, trabeculectomy had a higher incidence of hypotony, and the MicroShunt had a higher rate of device-related interventions.