All patients have newly diagnosed CMV retinitis and have completed a 14-day course of intravenous ganciclovir or foscarnet induction therapy within 1 week prior to study entry. The maintenance period consists of a 12-week study period followed by a 40 week follow-up period. Treatment consists of either combined sequential daily maintenance therapy of both foscarnet and ganciclovir or alternating daily treatment with ganciclovir one day and foscarnet the following day.