DOSE-RELATED DIFFERENCE IN PROGRESSION RATES OF CYTOMEGALOVIRUS RETINOPATHY DURING FOSCARNET MAINTENANCE THERAPY

PURPOSE: A previous dose ranging study of foscarnet maintenance therap y for cytomegalovirus retinopathy showed a positive relationship betwe en dose and survival but could not confirm a relationship between dose and time to first progression. This retrospective analysis of data fr om that study was undertaken to determine whether there was a relation ship between dose and progression rates, which reflects the amount of retina destroyed when progression occurs. METHODS: Patients were rando mly given one of two foscarnet maintenance therapy doses (90 mg/kg of body weight/day [FOS 90 group] or 120 mg/kg of body weight/day [FOS-12 0 group] after induction therapy. Using baseline and follow up photogr aphs and pre established definitions and methodology in a masked analy sis, posterior progression rates and foveal proximity rates for indivi dual lesions, selected by prospectively defined criteria, were calcula ted in each patient. Rates were compared between groups. RESULTS: The following median rates were greater for the FOS-90 group (N = 8) than for the FOS-120 group (N = 10): greatest maximum rate at which lesions enlarged in a posterior direction (43.5 vs 12.5 mu m/day; P = .002); posterior progression rate for lesions closest to the fovea (42.8 vs 5 .5 mu m/day; P = .010); and maximum foveal proximity rate for either e ye (32.3 vs 3.4 mu m/day; P = .031). CONCLUSION: Patients receiving hi gher doses of foscarnet have slower rates of progression and therefore less retinal tissue damage during maintenance therapy. A foscarnet ma intenance therapy dose of 120 mg/kg of body weight/day instead of 90 m g/kg of body weight/day may help to preserve vision in patients with c ytomegalovirus retinopathy.