Glaucoma Drainage Devices Versus Trabeculectomy in Refractory Glaucoma

Abstract

Introduction: Trabeculectomy with mitomycin C (MMC) is standard for uncontrolled glaucoma. Glaucoma drainage devices (GDD) (Ahmed, Baerveldt) are alternatives for refractory cases (prior failed surgery, neovascular, uveitic). Methods: Systematic review of 7 RCTs (n=1,089) comparing GDD versus trabeculectomy-MMC with ≥2 years follow-up. Primary outcome: intraocular pressure (IOP) reduction and failure (IOP >21 mmHg or <20% reduction). Secondary: reoperation rate, complications. Results: Mean IOP reduction was similar (GDD: 40% vs trab: 41%, p=0.77). Failure rate: GDD 29% vs trab 33% (HR 0.85, p=0.19). GDD had lower hypotony (2% vs 12%, p<0.001) but higher diplopia (8% vs 1%, p=0.002) and corneal decompensation (5% vs 2%, p=0.04). Reoperation for uncontrolled IOP was similar. Discussion: GDD is non-inferior to trabeculectomy with fewer hypotony complications but more diplopia. Choice depends on corneal status and risk tolerance. Conclusion: Glaucoma drainage devices are preferred in eyes with high hypotony risk (e.g., uveitic glaucoma).