Ahmed and baerveldt in glaucoma surgery: what is the safest choice? - a systematic review and meta-analysis

Background/Aims: Glaucoma drainage devices (GDDs) are essential in managing complex glaucoma cases. This review focuses on the Ahmed glaucoma valve (AGV) and Baerveldt glaucoma implant (BGI), the most commonly used GDDs. We aim to evaluate complications associated with AGV and BGI, particularly post-operative hypotony. Methods: We systematically reviewed randomized controlled trials (RCTs) and non-randomized studies (NRSs) comparing AGV and BGI. The primary outcome was persistent hypotony (IOP < 5 mmHg). Secondary outcomes included hypotony maculopathy, choroidal effusion, suprachoroidal hemorrhage, vision loss, cystoid macular edema, diplopia, corneal decompensation, endophthalmitis, hyphema, further surgery for IOP control, tube interventions, exposure, and occlusion. Results: Thirteen studies (4 RCTs, 9 NRSs) with 2,513 eyes were analyzed. AGV was associated with a lower incidence of persistent hypotony in RCTs (0.6% vs. 4.4%, p = 0.006), choroidal effusion (4.95% vs. 15.8%, p < 0.0001), vision loss (9% vs. 18.9%, p = 0.01), and cystoid macular edema (2.5% vs. 9.6%, p = 0.009). BGI showed a lower need for further surgery to control IOP in RCTs (14.5% vs. 7.5%, p = 0.01). No significant differences were found for other outcomes, including suprachoroidal hemorrhage, corneal decompensation, and tube-related complications. Conclusion: AGV seems to offers a safer profile with fewer hypotony-related complications compared to BGI. Personalized device selection is crucial for optimizing glaucoma surgery outcomes. Further high-quality, well-designed studies are needed to validate those results.