INTRAVITREAL INJECTION OF CIDOFOVIR IN CMV RETINITIS

Background: CMV retinitis is the most common opportunistic ocular infe ction and the main cause of blindness in AIDS patients with a T-helper cell count less than or equal to 50/mu l. Cidofovir is a nucleotide a nalogue with a long half-life time after phosphorylation intracellular ly. It is effective against CMV and can be given intravenously and int ravitreally. The aim was to offer an alternative therapy for CMV retin itis to patients who could not receive standard treatment because of c ontraindications or refused it. The efficacy and tolerance of intravit real injections of cidofovir should be evaluated. Patients and methods : We treated 16 eyes of 12 patients. The total number of injections wi th 15 mu g of cidofovir each was 49, with an average of 3 injections p er eye. The duration of follow-up was 75-295 days (median 170 days). P robenecid was given concomitantly. Injections were repeated after 6-10 weeks. Secondary prophylaxis of CMV organ infection was done with ora l ganciclovir. Results: Within a few days all areas with active retini tis turned into scars following the first injection. Under consequent treatment no reactivation was observed. Four eyes developed a mild iri tis with hypotony within a mean time of 12 days after injection. All r esponded rapidly to topical steroids. None had a persisting loss of vi sion. Two eyes developed cystoid macular edema (CME). Two patients slo pped anti-CMV treatment (ganciclovir orally and injections), followed by a recurrence after an average of 64 days. Conclusions: Intravitreal injection therapy with 15 mu g cidofovir and concomitant oral probene cid is a valuable and safe alternative treatment for CMV retinitis in AIDS patients. Its main complication is iritis with hypotony, which is effectively treatable with topical steroids. No complications caused by the injection technique itself were noted. The occasional observati on of CME in otherwise quiet eyes, however, is probably drug-related.