Treatment of experimental herpes simplex keratitis with acycloguanosine

Acycloguanosine, a recently developed compound with high inhibitory activity against viruses belonging to the herpes group, has been evaluated in experimental herpes simplex keratitis in rabbits in comparison with trifluorothymidine and preparations of idoxuridine and vidarabine at present in clinical use. All compunds were used in the form of ophthalmic ointments which were applied 5 times a day at intervals of 2 hours. Treatment began on the third day of infection and was continued for 4 days. Complete cure was obtained with acycloguanosine and idoxurdine; trifluorothymidine and vidarabine were considerably less effective. Acycloguanosine was equally effective when given intravenously in the form of its sodium salt, and could be detected in the tear fluid in inhibitory concentrations when given by mouth. The compound was relatively free from toxicity.