Two hundred twenty-five patients with AIDS and CMV retinitis are eligible for enrollment in Groups A, B, and C of the study, provided that each subject has received and tolerated a therapeutic course of intravenous (IV) ganciclovir of at least 4 weeks duration resulting in stable retinitis. An additional 100 subjects who have received and tolerated a course of IV or oral ganciclovir under any clinical trial of oral ganciclovir sponsored by Syntex Research and have stable retinitis may enter into Group D of this study and receive oral ganciclovir.