Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 46 4 2008 08 15 295 298 R Zarei Associate Professor of Ophthalmology, Eye Research Center, Tehran University of Medical Sciences, Te S Shahhosseini Ophthalmologist G Faragee-Oskouee Associate Professor of Ophthalmology, Eye Research Center, Tehran University of Medical Sciences, Te A. R Shokoh Ophthalmologist K Hamzehdoost Assistant Professor of Ophthalmology, Eye Research Center, Tehran University of Medical Sciences, Te 2015 09 28 The most common cause of failure during the first trimester after trabeculectomy is encapsulated bleb and needling bleb revision is a less invasive method in the management of refractory cases. The purpose of this study is to determine the efficacy and safety of mitomycin-C (MMC) augmented bleb revision of failed filtration surgery. This study is a before-after (paired) observation. 33 patients with failed trabeculectomy because of bleb encapsulation, whose intraocular pressure (IOP) was not reduced under 21 mmHg despite of medications and digital massage , underwent needling bleb revision and subconjunctival injection of 0.1 ml MMC (0.4 mg/ml).The mean follow-up time was 9.24 ± 5.27 months (1-20 months). Statistical analysis of the data included the paired two-tailed Student's t test for preoperative and postoperative IOP and number of medications. 36 needling procedures (mean, 1.09 ± 0.21 revisions per eye) were performed on 33 eyes. Patients were between 10-80 years old (mean, 45.67 ± 22.41 years) and mean follow-up was 9.24 ± 5.27 months. IOP decreased from 29.06 ± 5.03 mmHg to 18.21 ± 6.76 mmHg at last follow-up (P= 0.000). Antiglaucoma medications decreased from 2.18 ± 0.58 to 1.36 ± 0.29 at last follow-up (P= 0.000).Overall, 6 (18.2%) of 33 cases achieved a complete success and 20 (60.6%) of cases achieved a qualified success. The complications of this procedure were subconjunctival hemorrhage (17 cases), hyphema (5 cases) and conjunctival button hole (2 cases). Needling bleb revision with mitomycin-C appears to be an effective and relatively safe way to revive failed filtration surgery. https://acta.tums.ac.ir/index.php/acta/article/view/3486 https://acta.tums.ac.ir/index.php/acta/article/download/3486/3463