Bleb vascularity following post-trabeculectomy subconjunctival bevacizumab: A pilot study

Background: To determine whether postoperative subconjunctival bevacizumab significantly alters bleb vascularity. Design: A randomized, prospective interventional study. Participants: Forty-three eyes from 39 patients were recruited, with 21 eyes randomized to subconjunctival injections of 5-fluorouracil, and 22 eyes to combined 5-fluorouracil/bevacizumab. Methods: All patients who underwent uncomplicated primary antimetabolite augmented trabeculectomy who subsequently required postoperative subconjunctival 5-fluorouracil injection within 4 weeks of surgery were eligible. Patients were randomized to receive subconjunctival 5-fluorouracil only (7.5mg/0.15mL) or 5-fluorouracil plus bevacizumab (1.25mg/0.05mL). Main Outcome Measures: Primary outcome was bleb vascularity with secondary endpoints including visual acuity, intraocular pressure, bleb morphology, complications and total numbers of 5-fluorouracil injections were recorded at baseline, week 12 and 18 months. Results: At week 12, there was no significant difference between groups for visual acuity, intraocular pressure, bleb vascularity and morphology, or total number of 5-fluorouracil injections. By 18 months, 47.4% of the 5-fluorouracil/bevacizumab group exhibited central bleb avascularity compared with 21.1% of the 5-fluorouracil group (Fisher's exact test, P=0.17). Two bleb complications (one blebitis; one suture abscess) recorded in the 5-fluorouracil/bevacizumab group. Conclusions: After a single combined injection, a trend for increased central bleb avascularity was observed, although this effect was not sufficient to reach statistical significance. This, in addition to the occurrence of two bleb-related complications in the bevacizumab group, suggests the need for a larger clinical trial to further evaluate the safety and efficacy of bevacizumab as a modulating agent in glaucoma filtration surgery.