XEN-augmented Baerveldt drainage device implantation in refractory glaucoma: 1-year outcomes

Purpose To evaluate outcomes of XEN-augmented Baerveldt drainage device implantation in refractory glaucoma and factors predicting surgical success. Method All eyes undergoing XEN-augmented Baerveldt for refractory open-angle glaucoma at a tertiary glaucoma centre between January 2016 and November 2017 were retrospectively enrolled. Intraocular pressure (IOP), number of anti-glaucomatous medications and postoperative adverse events (AEs) were analysed for 1 year postoperatively. Surgical success was defined as achieving (1) an IOP <= 15 mmHg or (2) <= 18 mmHg, with or without (qualified) or without medications (complete). Any subsequent glaucoma surgery was considered failure. Results Out of 60 eyes enrolled, 12-month data were available for 41 eyes (71.4%). Mean age was 64.7 +/- 23.1 years (50% female). Following surgery, IOP decreased significantly from a baseline of 29.9 +/- 13.2 to 15.2 +/- 6.6 mmHg (- 49.2%; P < 0.0001) at 12 months. Anti-glaucoma medications decreased from 3.0 +/- 1.3 to 1.3 +/- 0.9. Complete success was achieved by 14.6% of eyes using both the <= 15 mmHg and the <= 18 mmHg thresholds, and qualified success was achieved in 43.9% and 48.8%, respectively. Throughout the follow-up period, AEs were observed in 51.2% (hypotony = 24.4%; XEN blockage = 17.1%; displacement of XEN gel stent = 4.9%; hyphema = 4.9%). The 12-month success rate was significantly higher in patients who presented an IOP <= 10 mmHg at 1 week (58.6%, P = 0.001). Overall, 41.5% of patients required reoperation at 12 months (58.8% revision of the surgery; 41.2% transscleral cyclodestruction). Conclusion XEN-augmented Baerveldt is a safe and moderately effective technique to reduce IOP and anti-glaucoma medications in refractory glaucoma. IOP at 1 week seems to be a predictor for surgical success. Nevertheless, a high proportion of patients requires reoperation.