Management of viral retinitis.

Cytomegalovirus, herpes simplex, and herpes zoster are responsible for the majority of cases of viral retinitis. Herpes zoster also has been strongly incriminated as a causal agent in acute retinal necrosis. Effective chemotherapy exists for retinitis caused by herpes simplex and herpes zoster, along with acute retinal necrosis. Conventional antiviral therapy and immunomodulators are ineffective in the treatment of cytomegalovirus retinitis in patients with acquired immune deficiency disorder. Ganciclovir, a new antiviral agent, has significantly reduced visual morbidity in these patients. Recurrence of the infection is not uncommon while patients are on the drug or when the agent is discontinued, because ganciclovir is virostatic and does not stop viral replication in the retina. The inability to control this viral retinitis using presently available chemotherapy indicates a need to examine other therapeutic modalities.