title: Utility of real-time polymerase chain reaction in diagnosing and treating acanthamoeba keratitis.
abstract: OBJECTIVE
  Using real-time polymerase chain reaction (PCR), we detected Acanthamoeba and monitored the changes in Acanthamoeba DNA copy number over the treatment course in patients suspected of Acanthamoeba keratitis (AK).
  
  
  METHODS
  Subjects were 6 patients (average age, 26.2 years) suspected of AK at the Kinki University Outpatient Clinic. For detection of Acanthamoeba, patients' corneal scrapings were collected for smear analysis, culture, and real-time PCR. After the diagnosis of AK was confirmed, treatment was initiated based on the quantitative result of the real-time PCR.
  
  
  RESULTS
  Both the smear and culture were positive for Acanthamoeba in 4 cases and negative in 2 cases (agreement in 3 cases and disagreement in 2 cases). By real-time PCR, all 6 cases were positive for Acanthamoeba with an average DNA copy number of 4.8 ± 9.1 × 10 copies per sample. We further monitored the variation in the Acanthamoeba DNA copy number over the treatment course and successfully treated all the patients. DNA copy number provided a parallel with other clinical features of AK.
  
  
  CONCLUSIONS
  Real-time PCR can be a useful method for a rapid and precise diagnosis of AK. Moreover, utility of the Acanthamoeba DNA copy number obtained by real-time PCR can help ophthalmologists in making the best treatment decision.
authors.affiliation: Department of Ophthalmology, Kinki University School of Medicine, Nara Hospital, Nara, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Itahashi
authors.forename: Shiro
authors.initials: S
authors.lastname: Higaki
authors.forename: Masahiko
authors.initials: M
authors.lastname: Fukuda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mishima
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Shimomura
mesh_terms: D000048:Acanthamoeba / Q000235:genetics / Q000302:isolation & purification*; D015823:Acanthamoeba Keratitis / Q000175:diagnosis* / Q000188:drug therapy* / Q000469:parasitology; D000328:Adult; D000981:Antiprotozoal Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use; D003263:Contact Lenses, Hydrophilic / Q000469:parasitology; D003315:Cornea / Q000469:parasitology*; D056915:DNA Copy Number Variations; D016054:DNA, Protozoan / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008825:Miconazole / Q000008:administration & dosage / Q000627:therapeutic use; D009883:Ophthalmic Solutions; D060888:Real-Time Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D000981:Antiprotozoal Agents; D016054:DNA, Protozoan; D009883:Ophthalmic Solutions; D008825:Miconazole; D002710:Chlorhexidine