Needling after XEN gel implant: What’s the efficacy? A 1-year analysis

Abstract

Purpose:

To analyse the long-term efficacy and safety of bleb needling in glaucoma patients previously submitted to XEN implantation.

Methods:

Retrospective, observational study. Charts from patients who underwent XEN gel implant surgery between October 2015 and December 2017 were reviewed. Needling protocol involves use of Mitomycin C 0.2 mg/mL in an operating room. Primary outcome was defined as intraocular pressure (IOP) lowering efficacy at 12 months post-operative. Complete success was defined as a decrease in IOP > 20% and overall value <18 mmHg. Secondary outcomes included safety parameters (both intra and post-operative). Exploratory analysis of predictive factors for success were performed. Statistical analysis was performed using SPSS version 24.

Results:

About 94 charts were reviewed, with 18 patients (19%) having undergone needle revision. This salvage procedure was performed after 3.3 ± 3.4 months, achieving a mean IOP reduction of 8.3 ± 8.4 mmHg at 12 months after the procedure (pre-needling: 24.0 ± 5.2 mmHg vs 12th month: 13.5 ± 5.9 mmHg, p < 0.0001). Accordingly, success was achieved in 72% (complete success in 61% of cases). Among predictive factors, there was a higher tendency for success in patients on two types of medications or fewer pre-operatively, cases of standalone XEN surgery and patients with a higher IOP difference pre-needling – day 1. No vision-threatening complications were recorded.

Conclusion:

XEN salvage procedure with mitomycin C is a valid option in early bleb failure. This single intervention had a long-lasting effect on bleb survival, with almost two-thirds achieving long term significant drop-free IOP reduction.