Successful therapy of herpes hominis keratitis in rabbits by 5 iodo 5' amino 2'5' dideoxyuridine (AIU): A novel analog of thymidine

The efficiency of 5 iodo 5' amino 2'5' dideoxyuridine (AIU) in the therapy of experimental herpes keratitis in rabbits has been examined. Virus infections were established bilaterally in 40 animals using herpes simplex, type 1 (NIH strain 11124). Twenty four hours after infection the rabbits were divided into five matched groups of eight and each group was treated, double blind, with topical drugs at four hour intervals for a total of 72 hours. The solutions instilled were: (1) saline; (2) IdUrd, 1 mg.per milliliter; (3) AIU, 1 mg.per milliliter; (4) AIU, 4 mg. per milliliter; and (5) AIU, 8 mg.per milliliter. Each eye was examined daily for 12 days and graded independently by two ophthalmologists. Although IdUrd and AIU (8 mg.per milliliter) were effective therapeutically, IdUrd had a greater effect. The AIU at 1 and 4 mg. per milliliter were less active, but showed more rapid healing than the saline control. Viral recovery studies are consistent with the clinical observations. A second independent experiment, similar to that described above, gave essentially identical results. Although less potent than IdUrd, AIU does provide effective therapy for herpes keratitis.