Bleb needling revision with 5-fluorouracil in filtering blebs with chronic failure for over 6 months post-trabeculectomy: a 12-month prospective study

Abstract

Purpose: To evaluate the results of bleb needling revision with adjunctive 5-fluorouracil (5-FU) in chronic filtering bleb failure over 6 months post-trabeculectomy. Method: A prospective study of failed trabeculectomies in a glaucoma clinic between November 2017 and April 2019 were treated with bleb needling revision with 5-FU injection by the same glaucoma specialist and technique. A 27 gauge needle was used to achieve multiple punctures of subconjunctival fibrosis or encystment to attempted elevation of the scleral flap. In all cases, 0.1 ml of 50 mg/ml of 5-FU was then injected subconjunctivally superior to the reformed bleb, and topical prednisolone acetate and moxifloxacin were prescribed. Success was defined as target IOP achieved and maintained less than 21 mmHg without anti-glaucoma medication at 12 months after first needling. Patients were followed up and re-needled as required. Results: Needling was attempted on 51 eyes (30 eyes of POAG, 18 eyes of PACG and 3 eyes of secondary glaucoma). The mean number of needling procedures was 1.88 (range 1-10). Needling was successful in 41 (80.4 %) eyes. The average pre-needling IOP was 24.8 ± 12.6 mmHg and the average post needling IOP was 13.5 ± 7.4 mmHg (P < 0.001) at 12 months after first needling. The mean number of medications pre-needling was 2.6 ± 1.4 and post-needing was 0.3 ± 0.5 (P < 0.001). The mean time post trabeculectomy was 68 months (range 6-120 months). Prognostic factors for failure of needling revision was pre-needling IOP > 25 mmHg (HR = 3.1, P = 0.0003), needling revision ≥ 3 times (HR = 2.6, P = 0.0012) and history of repeated filtration surgery before performed this procedure (HR = 1.8, P = 0.011). Ten eyes (19.6 %) did not respond to needling; 6 eyes of POAG, 3 eyes of PACG and and 1 eye of secondary glaucoma which required revised trabeculectomy, glaucoma drainage device implantation and anti-glaucoma medication. Three eyes had complications; 2 hyphema and 1 hypotony and no other procedures were required. Conclusion: Late bleb needling revision with 5-FU injection is still an effective and lasting treatment for the majority of failed trabeculectomy and avoid further surgery included Thai patients. More than one needling is frequently necessary to achieve target IOP. The procedure is relatively safe, with a short operating time and is minimally invasive with less complications.