In rabbits which had recovered from primary corneal herpes, reactivation of virus or reappearance of corneal fluorescein staining or both could be repeatedly induced in the same animal by intramuscular administration of epinephrine in oil. Twelve of 22 such attempts at virus reactivation in five animals were followed by virus release. Reactivation of virus was not necessarily accompanied by the development of clinically visible lesions since only seven of the 12 episodes were associated with corneal staining with fluorescein. In one animal four recurrent episodes were induced over a 184-day period. Cultures following epinephrine stimulation indicated that virus was still present three to eight months after primary infection.
Laibson PR, Kibrick S. Reactivation of Herpetic Keratitis in RabbitII. Repeated Reactivations in the Same Host. Arch Ophthalmol. 1967;77(2):244-248. doi:10.1001/archopht.1967.00980020246019