INTRAVITREAL CIDOFOVIR (HPMPC) TREATMENT OF CYTOMEGALOVIRUS RETINITISIN PATIENTS WITH ACQUIRED-IMMUNE-DEFICIENCY-SYNDROME

Purpose: The authors previously conducted a pilot, dose-escalating stu dy which suggested that a 20-mu g dose of intravitreal cidofovir (HPMP C) may be safe and effective in treating cytomegalovirus (CMV) retinit is in humans. The purpose of this series is to expand the authors' pri or experience with the 20-mu g dose of cidofovir as the sole treatment for CMV retinitis in patients with acquired immune deficiency syndrom e. Methods: The study design was an unmasked consecutive case series t rial in a single-center institutional retina referral practice. Eligib le patients with acquired immune deficiency syndrome had active CMV re tinitis in at least one eye and no evidence of extraocular CMV disease . Patients received a 20-mu g cidofovir trans pars plana injection and were treated with concomitant oral probenecid. Retreatments were perf ormed for progression of retinitis as determined by serial fundus phot ographs judged independently by three observers. The primary outcome w as time to retinitis progression determined by Kaplan-Meier analysis. Both globes of one patient who had unilateral retinitis were examined pathologically. Results: There were 37 cidofovir injections in 24 eyes of 17 patients. The median time to retinitis progression after the in itial 24 injections was 55 days. The median time to retinitis progress ion after 8 repeat cidofovir injections was 63 days. There was a signi ficant decrease in intraocular pressure from baseline to both 2 and 4 weeks after injection. A mild to moderate iritis developed in five (20 .8%) eyes that responded well to topical medications. Results of histo pathologic examination of one treated globe did not show any significa nt toxic effects. Conclusions: This study demonstrates that prolonged arrest of the progression of CMV retinitis may be obtained with a sing le 20-mu g cidofovir intravitreal injection. In addition, the effect o f the drug appears to be maintained after a second injection. The effe cts of cidofovir in causing uveitis and a slight lowering of the intra ocular pressure require further study.