Mitomycin C augmented glaucoma surgery: evolution of filtering bleb avascularity, transconjunctival oozing, and leaks

Abstract

Aims: To prospectively study the evolution of possible high risk features of conjunctival filtration blebs like avascularity, transconjunctival oozing (TCO), and leaks after mitomycin C (MMC) enhanced glaucoma surgery. Methods: Single observer, 2 year prospective study on bleb characteristics of 125 eyes of 125 consecutive patients who had MMC augmented glaucoma surgery with initially successful filtration. MMC (0.2 mg/ml for 2 minutes in most cases) was applied on the area of the scleral flap before dissection. Glaucoma surgeries included were trabeculectomy, deep sclerectomy, and combined procedures. A dry fluorescein strip was applied on the avascular part of the bleb and observed for aqueous egress with flow (point leak, PL) or without (TCO). Results: The mean time (95% CI) for observing bleb avascularity, TCO, and bleb leaks were 106 days (69 to 143), 208 days (155 to 261), and 609 days (559 to 659), respectively. Bleb leaks were observed in 17 eyes (13.6%)-15 (24.6%) in the trabeculectomy group and two (3.1%) in the deep sclerectomy group (p = 0.003). Kaplan-Meier survival analyses showed that the probability of observing bleb avascularity at sixth, 12th, and 24th month after surgery was 56%, 71%, and 73%, respectively. In eyes with avascular blebs, the probability of developing TCO and leaks was 77% and 1% at 6 months, 81% and 12% at 12 months, and 95% and 26% at 24 months, respectively. Cox's regression analyses and log rank tests showed that eyes with larger avascular blebs (.4 mm) were more likely to develop TCO (hazard ratio 3.77, p = 0.001) and delayed bleb leaks were more likely to be seen in eyes of the trabeculectomy group rather than the deep sclerectomy group (hazard ratio 0.06, p = 0.0006). Conclusions: MMC application over the area of scleral flap dissection during glaucoma surgery is associated with a high incidence of bleb avascularity, TCO, and delayed bleb leaks. Most eyes developed bleb avascularity within the first year after surgery. TCO will eventually be seen in all eyes with avascular blebs and the incidence of leaks gradually increases with time. This study shows that patients with eyes undergoing glaucoma surgery with MMC and avascular blebs should be monitored indefinitely.

Validation of the Glaucoma Filtration Surgical Mouse Model for Antifibrotic Drug Evaluation

“…We believe this is due in part to the suppression of angiogenesis at the wound site by MMC, which is known to have potent antiangiogenic properties (39). While a microvascular network was apparent around the operated site soon after wounding in the control mouse eye, the MMC-treated blebs were characterized by the lack of vasculature which corresponded with similar observations in the clinic (41). The suppression of angiogenesis is, however, a double-edged sword.…”

E-PTFE (Gore-Tex®) implant with or without low-dosage mitomycin-C as an adjuvant in penetrating glaucoma surgery: 2 year randomized clinical trial

“…In our experience, MMC can be regarded as an enhancement of the deep sclerectomy IOP-lowering effect without evidence of antimetabolite-related complications (Cillino et al 2005). On the other hand, MMC-augmented glaucoma surgery can be associated with a significantly higher frequency of late bleb leaks (Anand & Atherley 2005;Anand et al 2006). and Gaetano Lodato A detailed database search (Medline and PubMed) failed to show any report on the use of synthetic implant materials as adjuvants in penetrating glaucoma surgery (Jampel et al 2002;Wilkins et al 2005).…”

Deep sclerectomy with mitomycin C in eyes with failed glaucoma surgery and pseudophakia

“…24 While there is no reported study of comparison in morphology between DS and trabeculectomy blebs, we have reported that anterior limbal MMC application results in a high frequency of avascular and thinwalled blebs in both DS and trabeculectomy. 34 In trabeculectomy, intensive postoperative management may lead to lower IOPs in the long term. 35 Our postoperative regime for DS, besides topical steroids, consists of subconjunctival 5-FU injections for failing blebs, LGP and needle revision with subconjunctival MMC or 5-FU.…”