title: In vivo laser confocal microscopy findings of radial keratoneuritis in patients with early stage Acanthamoeba keratitis.
abstract: OBJECTIVE
  To investigate in vivo corneal changes of keratoneuritis in early stage Acanthamoeba keratitis (AK) using in vivo laser confocal microscopy.
  
  
  METHODS
  Single-center, prospective, clinical study.
  
  
  METHODS
  Thirteen eyes (12 patients; 5 men and 7 women; mean age ± standard deviation, 22.3 ± 4.2 years) with keratoneuritis resulting from early stage AK were included in this study.
  
  
  METHODS
  In vivo laser confocal microscopy was performed, paying special attention to keratoneuritis.
  
  
  METHODS
  Selected confocal images of corneal layers were evaluated qualitatively for shape and degree of light reflection of abnormal cells and deposits.
  
  
  RESULTS
  In all patients, Acanthamoeba cysts were observed clearly in the basal epithelial cell layer as highly reflective round particles with a diameter of 10 to 20 μm. Bowman's layer infiltration of Acanthamoeba cysts was observed in only 1 case, and no cases showed stromal or nerve infiltration of Acanthamoeba cysts. In the stroma, all cases showed highly reflective activated keratocytes forming a honeycomb pattern; these changes were significant around the keratoneuritis. Infiltration of inflammatory cells, possibly polymorphonuclear cells, was observed along with keratocyte bodies in all cases. Numerous highly reflective spindle-shaped materials were observed around the keratoneuritis. Most notably, highly reflective patchy lesions were observed around the keratoneuritis in 11 cases (84.6%). Inflammatory cells also were observed in the endothelial cell layer in 4 cases (30.8%).
  
  
  CONCLUSIONS
  In vivo laser confocal microscopy identified consistent corneal abnormalities around keratoneuritis in early stage AK patients, of which highly reflective patchy lesions may be characteristic of keratoneuritis. Further morphologic studies of corneas with early stage AK in a larger number of patients may elucidate the clinical significance of radial keratoneuritis and may help us to understand the interaction between Acanthamoeba organisms and host corneal cells or nerves.
authors.affiliation: Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan. kobaya@kenroku.kanazawa-u.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yokogawa
authors.forename: Natsuko
authors.initials: N
authors.lastname: Yamazaki
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Yosaburo
authors.initials: Y
authors.lastname: Oikawa
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tokoro
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Sugiyama
mesh_terms: D015823:Acanthamoeba Keratitis / Q000175:diagnosis* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000935:Antifungal Agents / Q000627:therapeutic use; D002710:Chlorhexidine / Q000627:therapeutic use; D003263:Contact Lenses, Hydrophilic / Q000469:parasitology; D003315:Cornea / Q000294:innervation*; D003389:Cranial Nerve Diseases / Q000175:diagnosis* / Q000188:drug therapy; D003646:Debridement; D054714:Echinocandins / Q000627:therapeutic use; D005260:Female; D006801:Humans; D017964:Itraconazole / Q000627:therapeutic use; D055666:Lipopeptides / Q000627:therapeutic use; D008297:Male; D000077551:Micafungin; D018613:Microscopy, Confocal; D009443:Neuritis / Q000175:diagnosis* / Q000188:drug therapy; D009882:Ophthalmic Nerve / Q000187:drug effects / Q000473:pathology*; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000935:Antifungal Agents; D054714:Echinocandins; D055666:Lipopeptides; D017964:Itraconazole; D000077551:Micafungin; D002710:Chlorhexidine