Characterization of a Murine Model of Recurrent Herpes Simplex Viral Keratitis Induced by Ultraviolet B Radiation

The authors characterized a murine model of herpes simplex virus (HSV) reactivation in which recurrent herpetic keratitis was obtained in up to 80% of animals. Five weeks after ganglionic latency was established in National Institutes of Health inbred mice after corneal inoculation, HSV type 1 (HSV-1) was reactivated by irradiating the previously inoculated eye with ultraviolet (UV) light. Comparison of different UV wavelengths showed UVB to be optimal for reactivation, with peak viral recurrence being induced by a total exposure of approximately 250 mJ/cm. 2 Reactivated infectious virus generally began to appear in trigeminal ganglia 2 days postirradiation and was subsequently detectable in the cornea by both corneal swabbing and immunostaining for viral antigens. Two consecutive outbreaks of viral recurrence at the ocular surface were induced in selected animals by serial exposure to UVB. Advantages of this model over other models of recurrent keratitis are discussed. Invest Ophthalmol Vis Sci 32:2741-2746,1991 Several animal models have been developed in an effort to reproduce different pathogenic aspects of recurrent herpes simplex virus (HSV) keratitis. Rabbits were used in many studies related to ocular herpetic disease and the subsequent latent infections established in the trigeminal ganglia. They were used in the first experimental production of recurrent herpetic eye disease 1 in which ultraviolet (UV) light was used to induce HSV recurrence in the eye. The UV irradiation, combined with ocular and systemic corticosteroid treatment, resulted in recurrent herpes keratitis with viral shedding in three of four rabbits. Subsequent experiments with rabbit models of herpetic eye disease used iontophoresis of epinephrine or other substances into the cornea 2 to induce viral shedding, although recurrent ocular lesions did not accompany this shedding in all cases. Unfortunately, the rabbit model of herpetic disease is prone to spontaneous reactivation of latent virus; therefore it is not ideal