A systemic treatment strategy for CMV retinitis is needed that will be effective yet convenient to administer, without the need for a permanent indwelling IV catheter. Although oral ganciclovir has been used as maintenance following induction with IV ganciclovir, patients with reactivation of disease must be reinduced IV. A fixed-schedule regimen in which oral and IV ganciclovir are alternated may prevent reactivation and progression of disease, as opposed to the current therapeutic strategy in which changes in therapy are event-driven. Also, the duration of intermittent IV therapy required to control disease may be short enough to eliminate the need for an indwelling catheter.