Purpose: To report the incidence of failing filtration blebs after trabeculectomy with mitomycin C and to report the outcome of needling procedures for failing filtration blebs in these eyes.
Methods: We conducted a retrospective analysis of 537 eyes of 434 patients who had trabeculectomy with mitomycin C and reviewed the clinical course of 441 eyes of 338 patients with a minimum of three months of follow-up.
Results: In 441 eyes of 338 patients followed up for three months or more after trabeculectomy with mitomycin C, 88 (20.0%) eyes from 85 patients underwent needle elevation of the scleral flap. Forty-nine (22.4%) of 219 eyes required needle revision after trabeculectomy alone, and 39 (17.6%) of 222 eyes after trabeculectomy combined with cataract extraction and intraocular lens implantation. Mean intraocular pressure (IOP) after needle revision (17.9 +/- 11.6 mm Hg) was significantly less than the mean preneedling IOP (27.1 +/- 10.4 mm Hg, P < .00001, paired Student's t test). Sixty-three eyes of 60 patients had a minimum of three months of postneedling follow-up. Successful pressure control, defined as an IOP of 22 mm Hg or less with or without topical glaucoma control medications, was achieved in 46 (73.0%) of 63 eyes. Unsuccessful outcomes correlated significantly with higher preneedling IOP (R = 0.28, P = .03, df = 61) and prior surgery involving conjunctival incisions (R = 0.53, P < .00001, df = 61).
Conclusions: Needle elevation of the scleral flap may provide significantly long-lasting pressure reduction in eyes with failing mitomycin C blebs. Higher success rates are achieved in eyes with fewer prior conjunctival incisions, eyes requiring a single needle revision, and eyes with lower preneedling IOP.