Herpes simplex keratitis: classification, pathogenesis and therapy

Abstract

Herpes simplex virus (HSV)-1 remains a common cause of unilateral corneal disease and the leading cause of corneal blindness in the developed world. Despite advances in therapy, HSV keratitis remains a significant public-health concern and a cause of significant ocular morbidity. The mainstays of therapy continue to be topical trifluridine or acyclovir, oral acyclovir and topical corticosteroids. There are numerous challenges ahead in the preventative therapeutic management of HSV keratitis. This is despite 20 years of intensive research towards understanding the virology and host-mediated responses to infection. There is increasing recognition of the role of transplantation in transmitting HSV directly or in activating quiescent HSV disease in patients undergoing keratoplasty for other primary diagnoses. The ability of HSV to establish latency, despite immunological recognition by the host, makes the prospects for the development of an effective vaccine by mimicking the host immune response to natural infection daunting. Therapeutic vaccination for ocular HSV-1 is hazardous conceptually owing to the possible role of HSV-1-specific immunity in mediating ocular damage. The host immune response, in an attempt to eliminate virus or reinfection of the cornea, cannot elicit immunomodulators that cause collateral damage to the cornea while eliminating the virus.

Keywords::

• cornea
• herpes simplex virus
• keratitis
• keratoplasty
• vaccination