Needle Revision of Failed Filtering Blebs Using 5- Fluorouracil and a Combined Ab-Externo and Ab-Interno Approach

Abstract

To evaluate a surgical technique to revise a failed filtering bleb using subconjunctival 5-Fluorouracil with a combined ab-externo and ab-interno approach. This study is a retrospective review of the outcome of 77 consecutive bleb revisions, with greater than 6-month follow-up, performed by a single glaucoma surgeon (MW). All eyes had previously functioning filtering blebs with currently inadequately controlled intraocular pressures (IOP) prior to the bleb revisions. All surgery was performed in the operating room, using a retrobulbar injection and a microscope. Visco-elastic was injected into the anterior chamber. 5-Fluorouracil (0.1 mL; 50 mg/ml) was infiltrated around the bleb. A 30-gauge needle was used to lyse subconjunctival fibrosis and episcleral scar tissue binding down the scleral flap, and elevate the scleral flap. Through an inferior paracentesis, a cyclodialysis spatula was used to confirm and enlarge the communication with the subconjunctival space. The main outcome measurements were IOP and number of glaucoma medications. A successful outcome was defined as a 20% reduction from baseline IOP and a maximum IOP of 18 mm Hg, with or without medications, and a minimal follow-up of 6 months. 52% of patients achieved success after one revision with an average follow-up of 29.6 ± 14.4 months. In successful cases, the mean IOP decreased from 22.7 ± 4.5 mm Hg to 11.3 ± 3.5 mm Hg and medications were reduced from an average of 2.2 ± 1.1 to 0.4 ± 0.7. Kaplan-Meier survival analysis calculated a success of 77% at 1 year, 68% at 2 years, and 58% at 3 years. In failed filtering blebs, needle revision with 5-Fluorouracil and a combined ab-externo and ab-interno approach results in high success and low complication rates. The outcome of this procedure compares favorably with previously reported revision techniques.