Retinal toxicity of 6-methoxypurine arabinoside (ara-M). A new selective and potent inhibitor of varicella-zoster virus.

The toxicity of a new antiviral agent, 6-methoxypurine arabinoside (ara-M), as a selective and potent inhibitor against varicella-zoster virus, was investigated after intravitreal injection in rabbit eyes. Intravitreal doses of ara-M ranging from 20 micrograms to 400 micrograms produced no retinal toxicity, as assessed by electroretinography and light and transmission electron microscopy. These data suggest a potential role for intravitreal ara-M in the antiviral treatment of varicella-zoster viral retinitis.