- CMV retinitis progression has occurred either 1) at the end of a 10 - 21 day induction course of ganciclovir (7.5 - 10 mg/kg/day in divided doses) or 2) during the first 28 days of maintenance ganciclovir therapy (5 mg (or more)/kg/day, at least 5 days/week) where maintenance therapy began within 1 week of completing induction therapy.