title: Changing trends in the incidence of bleb-related infection in trabeculectomy.
abstract: OBJECTIVE
  To investigate the incidence of late onset bleb-related infection (BRI) following Mitomycin C (MMC) augmented trabeculectomy procedures at a single institution.
  
  
  METHODS
  This was a retrospective case series analysis of late onset BRI, defined as either blebitis or endophthalmitis occurring at least 1 month following a glaucoma filtration procedure. Data collected from hospital charts included the position of the conjunctival flap base. Two cohorts were examined: the first a sample of 194 intraoperative MMC augmented trabeculectomies undertaken over a 4-year period from 1993 to 1997, and the second a sample of 764 MMC trabeculectomies performed in a 4-year period between the years 1999 and 2005.
  
  
  RESULTS
  A total of 11 cases of BRI (cumulative incidence 5.7%) were identified in the cohort from 1993 to 1997. BRI cases had trabeculectomies performed with a limbus-based conjunctival flap and presented at a median IQR 14.8 (9.4-42.9) months after surgery. In the 1999-2005 cohort, nine cases of BRI were identified (cumulative incidence 1.2%). All these BRI cases had a fornix-based conjunctival flap and presented at a median IQR 19.2 (6.1-44.1) months after trabeculectomy surgery.
  
  
  CONCLUSIONS
  This study found that the incidence of BRI was higher in MMC augmented trabeculectomy shortly after the introduction of MMC, but subsequently reduced to a lower level. While many changes in surgical technique had occurred in the intervening period, the most significant change was from limbus-based to fornix-based conjunctival flap. However, the retrospective nature of the study prevents the authors from concluding that there is a causative relationship between changes in surgical technique and BRI.
authors.affiliation: Glaucoma Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.
authors.forename: Poornima
authors.initials: P
authors.lastname: Rai
authors.forename: Aachal
authors.initials: A
authors.lastname: Kotecha
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kaltsos
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Ruddle
authors.forename: Ian E
authors.initials: IE
authors.lastname: Murdoch
authors.forename: Catey
authors.initials: C
authors.lastname: Bunce
authors.forename: Keith
authors.initials: K
authors.lastname: Barton
mesh_terms: D000328:Adult; D000368:Aged; D000477:Alkylating Agents / Q000008:administration & dosage*; D003131:Combined Modality Therapy; D003228:Conjunctiva / Q000601:surgery*; D009877:Endophthalmitis / Q000453:epidemiology* / Q000382:microbiology; D015817:Eye Infections / Q000453:epidemiology* / Q000382:microbiology; D005901:Glaucoma / Q000601:surgery; D006801:Humans; D015994:Incidence; D008485:Medical Audit; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage*; D012189:Retrospective Studies; D013524:Surgical Flaps; D014130:Trabeculectomy / Q000706:statistics & numerical data*; D006113:United Kingdom / Q000453:epidemiology; D014792:Visual Acuity
chemical_list: D000477:Alkylating Agents; D016685:Mitomycin