ANTERIOR NONGRANULOMATOUS UVEITIS AFTER INTRAVITREAL HPMPC (CIDOFOVIR) FOR THE TREATMENT OF CYTOMEGALOVIRUS RETINITIS - ANALYSIS AND PREVENTION

Background and Objective: The authors characterize and analyze the inc idence of a previously reported mild anterior nongranulomatous uveitis associated with intravitreal injections of S)-1-(3-hydroxy-2-phosphon ylmethoxypropyl)cytosine (HPMPC), also termed cidofovir (Vistide, Gile ad Sciences, Foster City, CA). This is an acyclic nucleoside phosphona te analogue with a potent anticytomegalovirus effect. The authors also analyzed the effects of probenecid therapy, as well as prophylaxis wi th probenecid plus topical corticosteroids and cycloplegics on the cou rse and outcome of the uveitis. Methods: Prospective case series from a tertiary referral center, which included 46 consecutive patients wit h acquired immune deficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis. There was a total of 130 injections in 69 eyes treated wit h 20 mu g of intravitreal HPMPC. Forty-one patients (119 injections) r eceived oral probenecid, 5 patients (11 injections) did not, and 21 pa tients (53 injections) received topical corticosteroids and cycloplegi cs as an adjuvant to probenecid in the prophylaxis of iritis. Results: Mild to moderate nongranulomatous iritis was seen in 26% of patients after their first injection (n = 12). Patients receiving probenecid pr ophylaxis after first injection had a significantly lower frequency of iritis versus patients who did not receive probenecid at the time of first injection (P = 0.0089). In contrast, treatment with topical cort icosteroid and cycloplegics after injection did not statistically sign ificantly affect the frequency of iritis in patients (P = 0.44). The d evelopment of iritis after a second injection of HPMPC was more likely if it had occurred after the initial injection (P = 0.015; Fisher's e xact test). All cases of iritis were treated with topical corticostero ids and cycloplegics, and there was no permanent impairment of vision secondary to iritis after HPMPC injection in any eyes. Conclusions: An terior uveitis was seen in 26% of patients after first-time HPMPC inje ction. Concomitant use of probenecid appears to decrease the frequency of the iritis from 71% to 18% in patients with AIDS and CMV retinitis after the first intravitreal injection of HPMPC. Topical corticostero id administration after injection (before iritis) was ineffective in p reventing iritis treatment with topical corticosteroids and cycloplegi cs resulted in resolution of all iritis cases.