title: Primary varicella-zoster keratitis: diagnosis by polymerase chain reaction.
abstract: OBJECTIVE
  To report the value of polymerase chain reaction in the diagnosis of a worsening corneal ulcer.
  
  
  METHODS
  A 6-year-old boy underwent an emergent penetrating keratoplasty for a corneal ulcer that continued to worsen despite intensive antibiotic therapy.
  
  
  RESULTS
  Examination of the corneal specimen by polymerase chain reaction was positive for varicella-zoster virus but negative for herpes simplex. Based on polymerase chain reaction studies, we diagnosed primary varicella-zoster keratitis with corneal perforation. Electron microscopy showed herpetic virus particles in the cornea.
  
  
  CONCLUSIONS
  Polymerase chain reaction analysis of corneal buttons at the time of penetrating keratoplasty may benefit patients with undiagnosed recalcitrant corneal ulcers.
authors.affiliation: Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston 02114, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Power
authors.forename: R N
authors.initials: RN
authors.lastname: Hogan
authors.forename: S
authors.initials: S
authors.lastname: Hu
authors.forename: C S
authors.initials: CS
authors.lastname: Foster
mesh_terms: D002675:Child, Preschool; D003315:Cornea / Q000473:pathology / Q000821:virology; D016039:Corneal Transplantation; D003320:Corneal Ulcer / Q000601:surgery / Q000821:virology; D006562:Herpes Zoster / Q000175:diagnosis*; D014645:Herpesvirus 3, Human / Q000302:isolation & purification; D006801:Humans; D007634:Keratitis / Q000175:diagnosis* / Q000821:virology*; D015948:Keratoplasty, Penetrating; D008297:Male; D008854:Microscopy, Electron; D016133:Polymerase Chain Reaction