Inclusion Criteria

Concurrent Medication:

Allowed:

• Topical anti-Herpesvirus agents.
• Zidovudine (AZT) for patients in deferral or foscarnet treatment groups:
• 100 mg every 4 hours. For patients on ganciclovir:
• 100 mg every 8 hours.
• Dideoxyinosine (ddI) and other antiretroviral available via expanded access programs, investigational triazoles, granulocyte-macrophage colony-stimulating factor, and erythropoietin to treat marrow toxicity. The use of other investigational drugs will be considered on a drug by drug basis.
• It is not recommended that patients receiving ganciclovir take AZT simultaneously. If AZT is prescribed for patients taking ganciclovir, it should be prescribed at reduced doses and discontinued if hematologic toxicity develops.

Patients must have:

• Diagnosis of AIDS by CDC criteria or a documented HIV infection.
• Cytomegalovirus (CMV) retinitis that does not require surgical intervention diagnosed in one or both eyes by a SOCA-certified ophthalmologist.
• The means available for compliance with follow-up visits (including a caregiver if necessary).
• Must consent to study or consent of parent or guardian if less than 18 years of age.
• Willingness to take reduced dose of zidovudine (AZT) if dictated by treatment assignment.
• Willingness to discontinue other systemic treatments for Herpesvirus infections while receiving foscarnet or ganciclovir.

Prior Medication:

Allowed:

• Zidovudine (AZT).

Exclusion Criteria

Co-existing Condition:

Patients with the following conditions or symptoms are excluded:

• Sufficient media opacities to preclude fundus photographs in both eyes.

Concurrent Medication:

Excluded:

• Other systemic treatments for Herpesvirus infections.
• Other anti-cytomegalovirus therapy.
• Excluded with foscarnet:
• Parenteral pentamidine, amphotericin B, or aminoglycosides.
• Use of marrow toxic agents with ganciclovir and nephrotoxic agents with foscarnet is discouraged, and alternative treatment should be used whenever possible.

Patients with the following are excluded:

• Sufficient media opacities to preclude fundus photographs in both eyes.
• Known or suspected allergy to one of the study medications.

Prior Medication:

Excluded:

• Foscarnet or ganciclovir used previously to treat cytomegalovirus (CMV) retinitis.
• Excluded within 14 days of study entry:
• CMV hyperimmunoglobulin or other anti-CMV agents.
• Excluded within the past 28 days:
• Anti-CMV therapy.

Active intravenous drug or alcohol abuse, sufficient in the investigator's opinion to prevent adequate compliance with study therapy and follow-up.