title: Recurrent ocular herpes simplex keratitis following excimer laser photorefractive keratectomy in a rabbit model.
abstract: OBJECTIVE
  Reactivation of latent herpes simplex virus (HSV) by excimer laser photorefractive keratectomy(PRK) has been reported previously in the literature. This study evaluates the extent of such HSV reactivation and determines whether corneal de-epithelialization prior to PRK or the laser treatment itself induces this response.
  
  
  METHODS
  Twenty three normal 1.5-2.5 kg New Zealand white rabbits were infected on the surface of the cornea with HSV-1, strain RE. The animals were monitored until resolution and then divided into two treatment groups: 1) de-epithelialization alone, and 2) de-epithelialization plus laser. Animals were evaluated in a masked fashion by clinical examination and viral cultures twice a week through day 28.
  
  
  RESULTS
  The reactivation rate for group 1 (de-epithelization alone) was 0.0%, and for group 2 (PRK) was 67% by slit lamp biomicroscopy. Viral culture positivity rate matched these findings.
  
  
  CONCLUSIONS
  Excimer laser (193 nm) treatment can trigger viral shedding and reactivation of herpetic ocular disease in the latently infected rabbit. De-epithelialization alone is not sufficient to cause such viral reactivation or keratitis. Our findings suggest that patients with a history of herpetic keratitis undergoing PRK are at increased risk of HSV reactivation as a result of exposure to the excimer laser.
authors.affiliation: Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Epstein
authors.forename: E M
authors.initials: EM
authors.lastname: Fisher
authors.forename: G J
authors.initials: GJ
authors.lastname: Sternberg
authors.forename: W
authors.initials: W
authors.lastname: Franklin
authors.forename: R
authors.initials: R
authors.lastname: Gordon
authors.forename: J J
authors.initials: JJ
authors.lastname: Ho
authors.forename: P A
authors.initials: PA
authors.lastname: Asbell
mesh_terms: D000818:Animals; D003315:Cornea / Q000382:microbiology* / Q000473:pathology; D005260:Female; D018259:Herpesvirus 1, Human / Q000254:growth & development*; D016849:Keratitis, Herpetic / Q000209:etiology* / Q000473:pathology; D054018:Lasers, Excimer; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D011817:Rabbits; D012008:Recurrence; D012307:Risk Factors; D014775:Virus Activation; D017735:Virus Latency; D017201:Virus Shedding