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

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.

Needling revision with marking maneuver to locate the scleral flap

Purpose: To report a variation of the classical needle revision maneuver with an external marking of the scleral flap, augmented with mitomycin C (MMC) in failed non penetrating deep sclerectomy (NPDS). Method: This observational prospective pilot study included five consecutive patients who underwent an MMC needling revision of failed NPDS with the external marking of the scleral flap. All participants underwent a complete ophthalmologic examination and data were collected preoperatively as well as 1 day, 1 week and 1 month after the surgery. The surgical site was also evaluated during the procedure. Results: A significant reduction of IOP and antiglaucomatous medication from preoperative levels was detected at the end of the follow-up period. Regarding the surgical site, we succeed in locating the scleral flap and observing the bleb formation in all cases. No significant subconjunctival bleeding was detected. Conclusion: This variation of the classical needling technique seems to improve intrasurgical visualization and reduces complications, which might lead to an improvement in surgical success.

Development of an Infrared Monitor-Guided Bleb Revision Procedure

The needle revision procedure to address failing filtering blebs is a blind technique that might easily damage the scleral flap, conjunctiva, and choroid. We propose a new surgical procedure, infrared monitor-guided bleb revision, to perform bleb revision minimally invasively and effectively, and demonstrate the procedure in a patient. We developed the guided procedure with the infrared monitor to observe the bleb interior with greater contrast. Under the monitor, we dissect the hard fibrotic tissue with a bleb knife and, if necessary, remove adhesions using a needle and vitreous forceps. Finally, 5-fluorouracil is injected into the subconjunctiva. We have performed bleb revisions safely with clear visualization of the scleral flap using an infrared light. In the current case, the patient had good intraocular pressure control for about 1 year. The new infrared monitor-guided bleb revision procedure facilitates successful bleb revisions without damage to the underlying structures.

A rare case of endophthalmitis after bleb needle revision for glaucoma Xen® gel stent

Purpose: To describe the first case of endophthalmitis caused by Sphingobacterium spiritivorum, a glucose non-fermenting Gram-negative rod, in a patient previously implanted with a Xen® gel stent. Case report description: An 83-year-old patient, affected by open-angle glaucoma and with a previous surgery of combined cataract extraction and Xen gel stent implantation, developed endophthalmitis 1 month after bleb needle revision with 5-fluorouracil injection. At presentation, best corrected visual acuity was hand movement, hypopyon was evident into the anterior chamber and a flat bleb with no sign of leakage was present over the Xen gel implant. Outcome: Immediate pars plana vitrectomy was performed, with intravitreal antibiotic administration and silicon oil tamponade. S. spiritivorum was isolated from vitreous bacterial culture. According to the antibiogram, patient was treated with topical fortified ceftazidime eyedrops and appropriate systemic antibiotics (intravenous meropenem, 500 mg every 8 h for 7 days, followed by oral cotrimoxazole, 160 + 800 mg, twice a day for 10 days). After 2 weeks of treatment, ocular inflammation was resolved, best corrected visual acuity was 0.1 (Snellen chart) and intraocular pressure was 18 mm Hg without topical hypotensive therapy. Conclusion: S. spiritivorum was isolated for the first time as a causative agent of endophthalmitis in humans. Bleb needle revision in patients with Xen gel implant is not free of complications, and an attentive follow-up is required.

Needle revision outcomes after glaucoma filtering surgery: survival analysis and predictive factors

Purpose: To evaluate the efficacy and safety of needle revision and examine factors predictive of failure. Methods: In total, 157 eyes of 131 patients that underwent needle revision augmented with either 5-fluorouracil or betamethasone for trabeculectomy failure were included in this retrospective study. Complete failure was defined as additional glaucoma surgery, ciliodestructive procedures, loss of light perception, sight-threatening complications, hypotony maculopathy, and surgical bleb revision. Success was defined as intraocular pressure ⩽ 18 (criterion A), ⩽15 (criterion B), and ⩽12 mmHg (criterion C) reached with (qualified) or without (complete) medications, and absence of any criteria of complete failure. Results: The median (interquartile range) follow-up was 25.0 (41.0) months. Complete failure rates were 19%, 26%, and 31% at 1, 2, and 3 years, respectively. For criterion A, qualified and complete success rates were, respectively, 77% and 69% at 1 year, 66% and 51% at 2 years, and 60% and 47% at 3 years. For criterion B, qualified and complete success rates were, respectively, 67% and 61% at 1 year, 48% and 42% at 2 years, and 44% and 39% at 3 years. For criterion C, qualified and complete success rates were, respectively, 43% and 41% at 1 year, 27% and 25% at 2 years, and 24% and 23% at 3 years. High baseline intraocular pressure and primary surgery were associated with higher and lower risks of complete failure, respectively. Conclusion: Needle revision is an effective and safe procedure to rescue failing trabeculectomy postponing or avoiding further glaucoma surgery. Eyes with low target intraocular pressure may have poor long-term outcomes.