Treatment of Cytomegalovirus Retinitis in Patients with AIDS

Cytomegalovirus (CMV) is among the most common opportunistic infections in patients with the acquired immunodeficiency syndrome (AIDS) [1-3]. In the era of prophylaxis for Pneumocystis carinii pneumonia, disease caused by CMV has been reported to affect as many as 45% of patients with AIDS at some time during the course of disease [2]. Although CMV may affect the eyes, gastrointestinal tract, lungs, and central nervous system, CMV retinitis accounts for 85% of all CMV disease in patients with AIDS [3]. Untreated CMV retinitis spreads through the retina and causes total retinal destruction and blindness [4, 5]. Hence, CMV retinitis is a major cause of morbidity in patients with AIDS.

As of 1 May 1996, the treatments approved by the Food and Drug Administration (FDA) for CMV retinitis were intravenous ganciclovir, intravenous foscarnet, oral ganciclovir (for maintenance therapy), and the sustained-release ganciclovir intraocular device. Intravenous cidofovir was recommended for approval by the FDA Antiviral Advisory Committee in March 1996 but has not yet received full approval. Systemically administered drugs for treatment of CMV retinitis are given in two steps: An initial high dose is given to control the infection (induction), and then a lower dose is given to prevent relapse (maintenance). Although it suppresses viral replication, treatment does not eliminate CMV from the retina [6]; thus, discontinuation of therapy results …