title: Confocal Laser Endomicroscopy in Inflammatory Bowel Disease--A Systematic Review.
abstract: OBJECTIVE
  Confocal laser endomicroscopy is an endoscopic method that provides in vivo real-time imaging of the mucosa at a cellular level, elucidating mucosal changes that are undetectable by white light endoscopy. This paper systematically reviews current indications and perspectives of confocal laser endomicroscopy for inflammatory bowel disease.
  
  
  METHODS
  Available literature was searched systematically for studies applying confocal laser endomicroscopy in Crohn's disease or ulcerative colitis. Relevant literature was reviewed and only studies reporting original clinical data were included. Next, eligible studies were analysed with respect to several parameters, such as technique and clinical aim and definitions of outcomes.
  
  
  RESULTS
  Confocal laser endomicroscopy has been used for a wide range of purposes in inflammatory bowel disease, covering assessment of inflammatory severity, prediction of therapeutic response and relapse and adenoma surveillance in patients with ulcerative colitis. Methods for measurement of the histological changes ranged from subjective grading to objective quantification analysed by computer-aided models. The studies derived their conclusions from assessment of histological features such as colonic crypts, epithelial gaps and epithelial leakiness to fluorescein.
  
  
  CONCLUSIONS
  Confocal laser endomicroscopy remains an experimental but emerging tool for assessment of inflammatory bowel disease. It is the only method that enables in vivo functional assessment of intestinal barrier function. There is great heterogeneity in the literature and no single approach has been validated and reproduced to the level of general acceptance.
authors.affiliation: Department of Gastroenterology and Gastrointestinal Surgery, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark ditlevrasmussen@dadlnet.dk.
authors.forename: Ditlev Nytoft
authors.initials: DN
authors.lastname: Rasmussen
authors.affiliation: Gastro Unit, Division of Endoscopy, Copenhagen University Hospital Herlev, Copenhagen, Denmark.
authors.forename: John Gásdal
authors.initials: JG
authors.lastname: Karstensen
authors.affiliation: Department of Pathology, Copenhagen University Hospital Herlev, Copenhagen, Denmark.
authors.forename: Lene Buhl
authors.initials: LB
authors.lastname: Riis
authors.affiliation: Gastro Unit, Division of Endoscopy, Copenhagen University Hospital Herlev, Copenhagen, Denmark.
authors.forename: Jørn
authors.initials: J
authors.lastname: Brynskov
authors.affiliation: Gastro Unit, Division of Endoscopy, Copenhagen University Hospital Herlev, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Vilmann
mesh_terms: D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000473:pathology*; D007413:Intestinal Mucosa / Q000473:pathology*; D018613:Microscopy, Confocal / Q000379:methods*
keywords: Confocal laser endomicroscopy; Crohn’s disease; advanced imaging; endoscopy; inflammatory bowel disease; ulcerative colitis