Adverse Events and Autopsy Findings after Intravitreous Cidofovir (HPMPC) Therapy in Patients with Acquired Immune Deficiency Syndrome (AIDS)

Objective: The purpose of the study is to evaluate the adverse events and autopsy findings in a series of consecutive 20-µg intravitreous cidofovir injections at a single institution. Design: The study design was a nonrandomized, consecutive case series. Participants: Seventy-six patients with acquired immune deficiency syndrome with cytomegalovirus retinitis were studied prospectively. Sixty-three patients had 1 month's follow-up or longer, and this comprised the study group. In addition, histopathologic findings from 18 eyes of 9 patients were studied at autopsy. Intervention: A total of 296 injections of 20 µg cidofovir were given in 115 eyes. Sixty-three patients who had 246 injections in 93 eyes had 1 month's follow-up or longer for the evaluation of adverse events. Main Outcome Measures: Postinjection chronic hypotony associated with permanent visual loss, transient hypotony, iritis, and its long-term sequela (posterior synechia and cataract, retinal detachment, extraocular cytomegalovirus involvement) were the outcomes of interest in this study. Additionally, light and electron microscopic studies of human eyes were performed. Results: The most severe adverse event was postinjection chronic hypotony. This phenomenon was associated with permanent visual loss. This was observed in 1 % of the injections and 3% of the eyes of the patients (95% confidence interval, 0%–6%). Transient hypotony associated with mild-to-moderate visual loss developed in 14%, but vision recovered to baseline levels in these eyes subsequently. Analysis showed that transient hypotony in the injected eye could predict postinjection chronic hypotony in the fellow eye (two-tailed Fisher's exact test, P = 0.02). The incidence of iritis was 32%; posterior synechia and cataract were the long-term sequela of the iritis and developed in 19% and 11 % of the eyes, respectively. The incidence of retinal detachment was lower (6%). Histopathologic evaluation of the eyes showed mild-to-moderate atrophy of the nonpigmented epithelium of the ciliary body and no other evidence of intraocular toxicity. Conclusions: The most serious adverse event was postinjection chronic hypotony, which occurred in 3% of eyes. Episodes of transient hypotony appear to indicate that the fellow eye was predisposed to chronic hypotony. Therefore, it may be prudent to give intravitreous injections at least 2 weeks apart in the fellow eye to evaluate the clinical response of the injected eye.