title: A systematic review of endophthalmitis after microincisional versus 20-gauge vitrectomy.
abstract: BACKGROUND
  Endophthalmitis is a rare but severe complication of vitrectomy.
  
  
  CONCLUSIONS
  Post-surgical endophthalmitis is suspected to be more frequent after microincisional (23- and 25-gauge) compared with standard (20-gauge) vitrectomy.
  
  
  METHODS
  We conducted a systematic review of studies that compared microincisional and standard vitrectomy by searching MEDLINE and EMBASE up to November 2012. We used the Bayesian meta-analysis method to compute the odds ratio (OR) of endophthalmitis. We conducted subgroup analyses to compare the effect of different incision types and use of perioperative antibiotics.
  
  
  RESULTS
  We identified 3 small randomized and 18 nonrandomized studies that reported 68 cases of endophthalmitis in 148 643 participants. The overall OR of endophthalmitis for microincisional versus standard vitrectomy was 2.3 (95% credible interval [CrI], 0.8-5.8). We found an increased risk of endophthalmitis using a microincisional straight approach compared with standard vitrectomy (OR, 15.1; 95% CrI, 2.01-179), but not for a beveled approach (OR, 0.82; 95% CrI, 0.23-2.28). The OR of studies that reported on mixed microincision was between these 2 values (OR, 4.4; 95% CrI, 1.32-14.3). We estimated that the overall rate of endophthalmitis with 20-gauge vitrectomy was 3 cases in 10 000 procedures, and the probability that a beveled microincision increases the rate of endophthalmitis to more than 6 or 9 events was small (no more than 5% or 1%, respectively).
  
  
  CONCLUSIONS
  We did not find an increased risk of endophthalmitis for microincisional vitrectomy compared with standard vitrectomy. The beveled approach seems to be safer than a straight approach, supporting the current recommendation of its adoption in microincisional vitrectomy. However, these findings must be interpreted cautiously because of the small number of endophthalmitis events reported from included studies.
authors.affiliation: Department of Ophthalmology, Ourense University Hospital, Ourense, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Govetto
authors.forename: Gianni
authors.initials: G
authors.lastname: Virgili
authors.forename: Francesca
authors.initials: F
authors.lastname: Menchini
authors.forename: Paolo
authors.initials: P
authors.lastname: Lanzetta
authors.forename: Ugo
authors.initials: U
authors.lastname: Menchini
mesh_terms: D016208:Databases, Factual; D009877:Endophthalmitis / Q000209:etiology*; D006801:Humans; D008866:Microsurgery / Q000379:methods*; D011183:Postoperative Complications; D012307:Risk Factors; D014821:Vitrectomy / Q000379:methods*