Background: Cytomegalovirus (CMV) retinitis is the most common intraocular infection in patients with the acquired immune deficiency syndrome (AIDS) and, untreated, is a blinding disorder. The Foscarnet-Ganciclovir Cytomegalovirus Retinitis Trial is a multicenter, randomized, controlled, unmasked, clinical trial that compared ganciclovir and foscarnet as treatments for CMV retinitis in patients with AIDS.
Methods: Patients with previously untreated CMV retinitis who enrolled in this trial were assigned randomly to treatment with either foscarnet or ganciclovir and followed at regular intervals for visual outcomes, including progression of the retinitis, visual acuity, and visual fields. In October 1991, the treatment protocol was suspended due to a greater mortality in the ganciclovir-assigned group.
Results: The efficacy of the two drugs in controlling the CMV retinitis as measured by the time to first progression was similar. The relative risk for progression of the retinitis was 0.97 (ganciclovir versus foscarnet; P = 0.833), and the median time to first progression was 53 days in the foscarnet-assigned patients compared with 47 days in the ganciclovir-assigned patients (P = 0.997), as determined by a masked reading at a central fundus photograph reading center. By 120 days after randomization, progression was observed in 85% of patients in each treatment group. Visual acuity outcomes were similar for both groups; at 6 months after randomization, 88% of the foscarnet-assigned patients and 93% of the ganciclovir-assigned patients had a best-corrected visual acuity of 20/40 or better in the better eye (P = 0.325). Visual field scores were similar in the two groups; in all eyes affected with CMV retinitis, there was a mean 29 degrees/month loss of visual field in foscarnet-assigned patients compared with a 31 degrees/month loss in ganciclovir-assigned patients (P = 0.674).
Conclusion: Although foscarnet was associated with a longer survival than ganciclovir, the two drugs appear equivalent in controlling CMV retinitis and preserving vision.