Materials and Methods: Forty eyes of 40 patients with bleb failure after trabeculectomy were included in this study. Repeated doses of 5mg of 5-fluorouracil (5-FU) were injected subconjunctivally in eyes with bleb failure after filtering surgery. The success was defined as an intraocular pressure (IOP) of ≤21 mmHg with or without medications. Intraocular pressure, the number of eyes using antiglaucomatous medications, frequency of 5- FU injection, variations of bleb appearance and complications were evaluated prospectively during the follow-up period.

Results: Primary open angle glaucoma in 12 eyes (30%), neovascular glaucoma in 10 eyes (25%), narrow angle glaucoma in 3 eyes (7.5%) and secondary glaucoma in 15 eyes (37.5%) were detected. When a decision of applying 5-FU injection was reached, mean IOP was 26.2±7.1mmHg. The mean IOP was 17.0±9.0 mmHg at the last follow-up examination. There was statistically significant difference between the pre-treatment and post-treatment IOP (p<0.001). 5-FU application was more successful in patients with primary glaucoma (p<0.05). Overall rate was 91.6% at 3 months, 85.7% at 6 months, 80% at 12 months and 63.6 %at 18 months. Follow-up time was 3-18 months. Punctate epiteliopathy in 9 (22.5%) eyes and corneal ulcers in 5 (12.5%) eyes were observed during follow-up period.

Conclusions: Low dose 5-FU application appears to improve bleb function in patients with bleb failure after trabeculectomy. Procedure is more successful in patients with primary glaucoma. The modified administration of 5-FU can result in fewer corneal complications. Keywords : Trabeculectomy, failing filtering bleb, 5-fluorouracil