Blind, controlled rabbit studies were done to determine the toxic effects on the cornea of idoxuridine (IDU) ointment (0.5%) and adenine arabinoside (Ara-A) ointment (3%), the clinically used concentrations. Neither antiviral agent was found to retard the rate of closure of large or small epithelial defects. However, the regenerating epithelium of the IDU-treated eyes showed signs of toxicity that were not present in the eyes treated with Ara-A or in control eyes. The strength of penetrating stromal wounds and the collagen content of these wounds was significantly and equally diminished in eyes treated with the IDU or Ara-A ointments, compared to eyes treated with control ointment.
Langston RHS, Pavan-Langston D, Dohlman CH. Antiviral Medication and Corneal Wound Healing. Arch Ophthalmol. 1974;92(6):509-513. doi:10.1001/archopht.1974.01010010523013