Abstract
Purpose :
Evidence on the safety and efficacy of microinvasive subconjunctival insertion of the XEN® trans-scleral gelatin stent for patients with glaucoma is limited. This study reports the long-term experience of XEN® ± cataract surgery in a large specialist glaucoma center with an ethnically diverse population.
Methods :
Retrospective case-note review of all XEN® surgery performed between 2012-2018 at Moorfields Eye Hospital.
Results :
436 eyes of 383 patients were included. The population was ethnically diverse (54% White, 19% Black, 19% Asian, 4% other). Mean patient age at the time of surgery was 65 (range 16-100). 53% were diagnosed with primary open angle glaucoma, 10% uveitic glaucoma, 7% primary angle closure glaucoma, 6% normal tension glaucoma, 3% ocular hypertension and 11% with other secondary glaucomas. Mean baseline intraocular pressure (IOP) (±SD) prior to surgery was 22.0±7.0mmHg (using 2.9±1.2 medications), reducing to 16.0±6.2mmHg at 6 months (using 0.9±1.2 medications), 15.2±4.7 mmHg at 1 year (using 1.4±1.3 medications), 14.7±4.2 mmHg at 2 years (using 1.2±1.3 medications) and 15.2±4.7 mmHg at 3 years (using 1.1±1.3 medications) in cases where no further glaucoma surgery or laser had been performed. 17% of eyes underwent at least one bleb needling procedure within 3 months of surgery. 35.8% of eyes underwent further surgery. 22.0% of eyes had revision surgery and 13.8% had further glaucoma surgery during follow-up (7.3% trabeculectomy and 6.4% tube surgery). Bleb-related infection was observed in 2.3% of cases over the follow-up period (0.9% bleb-related endophthalmitis, 1.4% blebitis). The overall failure rate (less than 20% IOP reduction with or without medication, further glaucoma surgery, loss of light perception) was 42% with a mean time to failure of 6.1±6.5 months.
Conclusions :
When successful, the XEN® gel stent can be an efficient intervention to lower intraocular pressure and reduce the burden of glaucoma medications for patients. However, the procedure may be associated with a high re-operation rate and a higher risk of bleb-related infection than expected with trabeculectomy and other types of glaucoma surgery. Refinement of surgical technique and careful patient selection may help to improve long-term clinical outcomes.
This is a 2020 ARVO Annual Meeting abstract.