2'-Nor-2'-deoxyguanosine is an effective therapeutic agent for treatment of experimental herpes keratitis

2'-Nor-2'-deoxyguanosine (2'NDG), previously reported by us to effectively treat acute herpes simplex infections in mice, was used therapeutically to significantly enhance healing of established herpetic corneal lesions and prevent stromal disease in rabbits. Treatment using 0.06% 2'NDG drops (5 times daily) starting 3 days after infection resulted in more rapid healing of corneal epithelial lesions, rapid resolution of conjunctival inflammation, and prevention of stromal clouding compared to placebo-treated animals. In comparative dose-response titrations, the relative potency of 2'NDG to acyclovir was 6.4, which was significant. In addition, soluble ophthalmic inserts were developed for delivery of 2'NDG. Once a day treatment using ophthalmic inserts which released 100 micrograms 2'NDG significantly enhanced corneal and conjunctival healing and prevented stromal disease; 2'NDG eye drops (100 micrograms) delivered once a day were also effective in inhibiting the progression of corneal lesions. These results indicate that 2'NDG may be therapeutically effective in treatment of herpes keratitis, and further suggest that for use as eye drops or in an ophthalmic insert, 2'NDG may be effective even if applied once per day.