Hypotony in the early postoperative period after MicroShunt implantation versus trabeculectomy: A registry study

Abstract

Purpose: A comparison of the safety and efficacy of the MicroShunt versus trabeculectomy in the early postoperative period, with a particular focus on hypotony. Methods: In this registry study, we evaluated 200 eyes of 200 glaucoma patients who underwent filtration surgery at Oslo University Hospital between 2017 and 2021. Of these patients, 100 had a Preserflo MicroShunt (Santen) implantation and 100 had a trabeculectomy procedure. The patients were examined per standard hospital protocol after filtration surgery. Data were extracted from the 4- and 8-week visits. We defined hypotony as intraocular pressure (IOP) < 6 mmHg. Results: The mean preoperative IOP was 20.6 ± 7.1 mmHg in the MicroShunt group and 21.6 ± 7.1 mmHg in the trabeculectomy group, and the patients used a mean of 3.0 ± 0.9 and 3.1 ± 0.9 glaucoma medications, respectively. After 8 weeks, IOP was reduced to 10.4 ± 5.4 mmHg and 11.3 ± 4.6 mmHg, respectively (p = 0.23). During the early postoperative period, hypotony was registered in 63% of the MicroShunt patients and in 21% of the patients in the trabeculectomy group (p < 0.001); and 11% and 1%, respectively, of the patients developed choroidal detachments (p < 0.003). One patient in the MicroShunt group required reoperation due to hypotony. Conclusions: In this registry study, we found that the Preserflo MicroShunt and trabeculectomy had equally satisfactory IOP-lowering effects during the early postoperative period. In this same period, a high number of patients in the MicroShunt group developed hypotony.