Thirty eyes of 26 patients with unilateral non-sight-threatening CMV retinitis were randomly assigned to one of two groups: (1) immediate therapy with a device designed to release ganciclovir into the vitreous cavity a over approximately a 4-month period or (2) deferred treatment. In patients with bilateral non-sight-threatening CMV retinitis, one eye was randomly assigned to receive a ganciclovir implant with the other eye assigned to deferred treatment. (Note: The original trial design included a third randomized arm using a 2 ug/hour device. This arm was dropped for logistical reasons after enrolling two patients.)