title: Low-dose postoperative transconjunctival application of mitomycin C in rabbit trabeculectomy.
abstract: OBJECTIVE
  Mitomycin C (MMC) is commonly administered during filtering surgery to enhance the success of the procedure. Unfortunately, the increased success rate is associated with complications, including late bleb leaks, endophthalmitis, and ciliary epithelial toxicity. The purpose of this study was to investigate a safe and effective dose regimen for MMC to reduce incidence of those complications.
  
  
  METHODS
  Trabeculectomy was performed in 36 rabbits. MMC was applied only during surgery, only one day after surgery, or once daily after surgery for 3 days at lower concentrations. Balanced salt solution (BSS) was administered during surgery to one group as a placebo. The time to bleb failure was determined and the eyes were evaluated histopathologically. Success and toxicity were compared for the different treatment groups.
  
  
  RESULTS
  The mean time until trabeculectomy failure was 2.83 days for the placebo group, 6.33 days with administration of MMC 0.5 mg/mL during surgery, 7.83 days with administration of MMC 0.5 mg/mL once after surgery, and 11, 9, and 4.83 days with administration of MMC 0.1 mg/mL, 0.05 mg/mL, or 0.025 mg/mL, respectively, once a day for 3 consecutive days. On electron microscopic examination of the ciliary epithelium, toxic effects were greatest with MMC concentrations of 0.5 mg/mL and were less with lower concentrations.
  
  
  CONCLUSIONS
  The effect of MMC on trabeculectomy survival was dependent on both the concentration and the method of administration. Lower concentrations with multiple postoperative administrations were as effective as but caused less ciliary body toxicity than intraoperative administration of higher concentrations.
authors.affiliation: Department of Ophthalmology and Visual Science, University of Texas Health Science Center, Houston, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: El-Harazi
authors.forename: R M
authors.initials: RM
authors.lastname: Feldman
authors.forename: G
authors.initials: G
authors.lastname: Villanueva
authors.forename: L
authors.initials: L
authors.lastname: Carter-Dawson
authors.forename: H
authors.initials: H
authors.lastname: Mietz
authors.forename: A Z
authors.initials: AZ
authors.lastname: Chuang
mesh_terms: D000477:Alkylating Agents / Q000008:administration & dosage* / Q000633:toxicity; D000818:Animals; D002924:Ciliary Body / Q000187:drug effects / Q000648:ultrastructure; D003228:Conjunctiva / Q000187:drug effects; D005260:Female; D016685:Mitomycin / Q000008:administration & dosage* / Q000633:toxicity; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D011817:Rabbits; D011897:Random Allocation; D012449:Safety; D014130:Trabeculectomy / Q000379:methods*
chemical_list: D000477:Alkylating Agents; D016685:Mitomycin