title: Impression cytology in eyes with clinical and confocal scan features of acanthamoeba keratitis.
abstract: OBJECTIVE
  To report impression cytology findings in specimens obtained from eyes with clinical and confocal microscopic features of Acanthamoeba keratitis (AK).
  
  
  METHODS
  In this interventional case series, impression cytology was obtained from corneas of patients with clinical and confocal microscopic features indicative of AK. Specimens were stained with Periodic acid-Schiff/Papanicolaou (PAS/PAP) and examined for the presence of PAS-reactive Acanthamoeba cysts and/or hyperchromatic pear-shaped trophozoites. All specimens were then decolorized and re-stained with calcofluor white (CFW) for the presence of chemofluorescent cysts.
  
  
  RESULTS
  Fifty-six eyes of 50 patients with mean age of 25.5±9.3 (range, 17 to 78) years were evaluated. Forty-one (82%) cases were female and 51 (91.1%) eyes had history of contact lens wear. PAS-reactive Acanthamoeba cysts and/or hyperchromatic pear-shaped trophozoites were identified in 53 eyes (94.6%), 2 of which demonstrated only trophozoite- like structures. CFW staining was able to reveal the presence of chemofluorescent cysts in all 51 specimens (91.1%) in which cysts had been demonstrated with PAS/PAP staining. Trophozoites were not detected with CFW due to background staining of the cellulose acetate strip used for impression cytology.
  
  
  CONCLUSIONS
  Corneal impression cytology, stained with PAS/PAP or with CFW, successfully detects Acanthamoeba and can be employed for early noninvasive diagnosis of AK.
authors.affiliation: Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran ; Central Eye Bank of Iran, Tehran, Iran.
authors.forename: Mozhgan
authors.initials: M
authors.lastname: Rezaei Kanavi
authors.affiliation: Central Eye Bank of Iran, Tehran, Iran.
authors.forename: Bagher
authors.initials: B
authors.lastname: Hosseini
authors.affiliation: Medical Student, Shahed University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Javadi
authors.affiliation: Central Eye Bank of Iran, Tehran, Iran ; Department of Pathology, Gastrointestinal and Liver Disease Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasser
authors.initials: N
authors.lastname: Rakhshani
authors.affiliation: Central Eye Bank of Iran, Tehran, Iran ; Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad-Ali
authors.initials: MA
authors.lastname: Javadi
keywords: Acanthamoeba Keratitis; Confocal Scan; Impression Cytology