Abstract
Purpose: :
Filtering procedures remain the most popular surgical option in medically refractory glaucoma, but may eventually fail due to scarring, obstruction or encapsulation. This retrospective study was designed to evaluate the efficacy of our previously published needling revision method, performed with Mitomycin C (MMC) rather than 5FU, in restoring filtering function and reducing the reliance on adjunctive medications in a largely Hispanic population.
Methods: :
28 eyes of 23 consecutive patients were studied, all having undergone major OR-based bleb needling revisions during 2008-10 for inadequate IOP-control. The surgical method was as previously described (Paris, Zhao, Sponsel 2004), but using a 1-minute intra-bleb cannulation of 0.6 ml of 0.4 mg/ml MMC instead of postoperative subconjunctival 5FU injections. Outcome measures were IOP, acuity, and number of anti-glaucoma medications.
Results: :
The patient population was 57% Hispanic, 30% Caucasian and 13% African American. Mean patient age was 72.3 ± 11 years. Two-thirds of eyes requiring the procedure had a form of chronic angle closure glaucoma, and the remainder had POAG. Both the mean IOP decrease and the decrease in anti-glaucoma medications at all 6 measured time intervals (1 wk, 2 wks, 1 mo, 2 mo, 6 mo, 1 yr) post-op were highly significant (p<0.0001), with no evident divergence of the Hispanic subpopulation’s IOP responses from those of the group as a whole. IOP decreased from a mean of 27.2 ± 10.6 mmHg pre-op to 10.6 ± 5.5 mmHg 2 months post-op (Δ -61%), and 15 ± 7.8 mmHg 6 months post-op (Δ -45%). A mean of 2.5 ± 1.5 medications were required preop vs 0.33 ± 0.73 six months post-op (Δ -88%), with 86% of eyes needing glaucoma meds prior to the procedure and only 16% thereafter. At six months, 60% of eyes had IOP ≤15 mmHg without meds, and 76% ≤18 mmHg. Visual acuity was stable or improved in 69% of cases. There was an improvement of ≥2 lines measured on the Acuity System 3.8 (Canela Software, Temecula, CA) in 23% of cases and a decline of ≥2 lines in 12% of cases. Ten patients experienced one or more period of hypotony, 3 had hyphema, and 2 had a bleb leak that required resuturing. Four patients required major re-operations.
Conclusions: :
Antimetabolite augmented needling revision appears to be a reasonably safe and reliable option for restoring bleb function in glaucomatous eyes with failed filters. Complications that may require timely remedial management can arise, but the generally positive benefit/risk ratio is compelling. This procedure appears to be an appropriate treatment option for failed, flattened or encapsulated blebs.
Keywords: intraocular pressure • wound healing • trabecular meshwork