In a 1-year study conducted at 29 US and European sites, a total of 527 patients with medically uncontrolled POAG were randomized to either Santen Microshunt surgery or trabeculectomy. Overall, the primary endpoint (≥20% IOP reduction and no medication increase) was met by 53.9% and 72.7% of Microshunt and trabeculectomy eyes, respectively. In the United States, mean year 1 IOP was 14.4 for Microshunt and 11.1 for trabeculectomy on an average of 0.6±1.1 and 0.3±0.8 medications, respectively. In the EU, year 1 IOP was 13.5 for Microshunt and 10.8 for trabeculectomy on an average of 0.6 ± 1.1 medications in both groups.

Overall, hypotony (IOP <6 mmHg) was reported in 26.8% (106/395) of Microshunt eyes and 45.0% (59/131) of trabeculectomy eyes. Needling was reported in 19.0% (75/395) of Microshunt and 8.3% (11/132) of trabeculectomy eyes. In this study, reported as a poster study at Virtual AAO by Joseph Panarelli, MD, the Microshunt led to IOP and medication reductions, with lower rates of hypotony than seen with trabeculectomy.