title: Impression cytology of the ocular surface: a review.
abstract: OBJECTIVE
  To historically review the technique of impression cytology as a minimally invasive diagnostic tool for ocular surface pathology.
  
  
  METHODS
  A comprehensive review of published literature cited in PubMed since the first description of impression cytology in 1977 up to date has been undertaken.
  
  
  RESULTS
  A wide range of processing methods have been adapted to the technique of impression cytology (from conjunctiva, cornea or limbus): regular light microscopy with different stainings, transmission and scanning electron microscopy, immunofluorescence, immunocytochemistry, polymerase chain reaction analysis, immunoblotting analyses, or flow cytometry. At present, it is widely used as a non-invasive alternative to the full-thickness biopsy for the obtention of epithelial cells from the ocular surface.
  
  
  CONCLUSIONS
  Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. In addition, and mainly during the last decade, its use as a research tool has experienced an enormous growth and has greatly contributed to the understanding of ocular surface pathology.
authors.affiliation: Instituto Universitario de Oftalmobiología Aplicada (IOBA), University of Valladolid, Ramón y Cajal, 7, E-47005 Valladolid, Spain. calonge@ioba.med.uva.es
authors.forename: Margarita
authors.initials: M
authors.lastname: Calonge
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Diebold
authors.forename: Victoria
authors.initials: V
authors.lastname: Sáez
authors.forename: Amalia
authors.initials: A
authors.lastname: Enríquez de Salamanca
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Vázquez
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Corrales
authors.forename: José M
authors.initials: JM
authors.lastname: Herreras
mesh_terms: D001706:Biopsy / Q000379:methods; D003229:Conjunctival Diseases / Q000473:pathology*; D003316:Corneal Diseases / Q000473:pathology*; D015352:Dry Eye Syndromes / Q000175:diagnosis; D004847:Epithelial Cells / Q000473:pathology; D006801:Humans