Outcomes of XEN45 gel stent using posterior small incision sub-tenon ab interno insertion (Semi-open) technique

Abstract

Purpose: To evaluate the 12-month outcomes of a novel posterior small incision sub-tenon ab interno technique of XEN stent insertion (‘Semi-open’). Method: Consecutive eyes underwent XEN stent insertion with the Semi-open technique by two surgeons between 1st July 2018 and 30th September 2019. All cases received subconjunctival injection of 0.1 mL of mitomycin C 0.2 mg/mL. Eyes with primary open angle glaucoma (OAG), secondary OAG or pseudophakic primary angle closure glaucoma (PACG) were included. Exclusion criteria were phakic PACG, uveitic or neovascular glaucoma and postoperative follow-up <12 months. Primary outcomes were defined by World Glaucoma Association guidelines. Secondary outcomes included change in glaucoma medications, needling rates and complications. Results: We included 37 consecutive eyes of 35 patients with primary OAG (n = 30), secondary OAG (n = 6) and pseudophakic PACG (n = 1). Thirty-one eyes (84%) received a standalone XEN implantation and 6 (16%) underwent XEN implantation combined with phacoemulsification. The IOP reduced from 19.6 ± 6.0 mmHg preoperatively to 11.2 ± 2.6 mmHg at 12 months (P < 0.01). The number of glaucoma agents reduced from 3.49 ± 1.14 preoperatively to 1.57 ± 1.36 at 12 months. At 12 months, qualified success was 97.3% and complete success was 32%, with one case requiring trabeculectomy. Needling was required in 19% of cases over the 12 month follow up. Complications included 19 cases of transient hypotony and 7 cases of transient choroidal effusion. There were no cases of exposure, bleb leak or bleb-related infection. Conclusion: Semi-open XEN technique achieves high surgical success rate in the medium-term with relatively low post-operative bleb needling rate.