title: Ocular herpes simplex virus type 1: is the cornea a reservoir for viral latency or a fast pit stop?
abstract: OBJECTIVE
  To present a review supporting and refuting evidence from mouse, rabbit, nonhuman primate, and human studies of herpes simplex virus type 1 (HSV-1) concerning corneal latency.
  
  
  METHODS
  More than 50 research articles on HSV-1 published in peer-reviewed journals were examined.
  
  
  RESULTS
  Infectious HSV-1 has been found in mouse denervated tissues and in tissues with negative cultures from the corresponding ganglion. However, the different mouse strains have shown varied responses to different strains of HSV, making it difficult to relate such findings to humans. Rabbit studies provide excellent evidence for HSV-1 corneal latency including data on HSV-1 migration from the cornea into the corneoscleral rim and on the distribution of HSV-1 DNA in the cornea. However, the available methods for the detection of infectious HSV-1 may not be sensitive enough to detect low-level infection. Infectious HSV-1 has been successfully isolated from the tears of nonhuman primates in the absence of detectable corneal lesions. The recurrence of corneal ulcers in nonhuman primates before the appearance of infectious HSV-1 in tears suggests that the origin of the HSV-1 is the cornea, rather than the trigeminal ganglion. Human studies presented evidence of both ganglion and corneal latency.
  
  
  CONCLUSIONS
  Understanding HSV-1 disease progression and the possibility of corneal latency could lead to more effective treatments for herpetic keratitis. However, it is unlikely that operational latency in the cornea will be definitively proven unless a new method with higher sensitivity for the detection of infectious virus is developed.
authors.affiliation: Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA 70112-2234, USA.
authors.forename: David P
authors.initials: DP
authors.lastname: Kennedy
authors.forename: Christian
authors.initials: C
authors.lastname: Clement
authors.forename: Richard L
authors.initials: RL
authors.lastname: Arceneaux
authors.forename: Partha S
authors.initials: PS
authors.lastname: Bhattacharjee
authors.forename: Tashfin S
authors.initials: TS
authors.lastname: Huq
authors.forename: James M
authors.initials: JM
authors.lastname: Hill
mesh_terms: D000818:Animals; D003315:Cornea / Q000294:innervation / Q000821:virology*; D004197:Disease Reservoirs / Q000821:virology*; D018259:Herpesvirus 1, Human / Q000502:physiology*; D006801:Humans; D016849:Keratitis, Herpetic / Q000821:virology*; D008251:Macaca; D051379:Mice; D011817:Rabbits; D012668:Trigeminal Ganglion / Q000821:virology; D017735:Virus Latency