INTRAOCULAR-PRESSURE AND AQUEOUS-HUMOR DYNAMICS IN PATIENTS WITH AIDSTREATED WITH INTRAVITREAL CIDOFOVIR (HPMPC) FOR CYTOMEGALOVIRUS RETINITIS

PURPOSE: To evaluate the decrease in intraocular pressure associated w ith cidofovir (1-[(S)-3-hydroxy-2-(phosphonomethoxy)propyl]cyto dihydr ate; HPMPC) intravitreal injections. METHODS: We followed up 97 eyes o f 63 patients with acquired immunodeficiency syndrome (AIDS) who had c ytomegalovirus retinitis and had been treated with up to nine 20-mu g intravitreal cidofovir injections. Measurements were taken at baseline , between 2 and 3 weeks, and at 5 to 6 Reeks after injections. Anterio r chamber fluorophotometry was studied in seven eyes (four patients) b efore and after injections, Ciliary body anatomy was evaluated in two patients. RESULTS: After the first intravitreal injection, mean intrao cular pressure was 2.2 mm Hg lower than that at baseline at 2 to 3 wee ks (P <.001) and 1.3 mm Hg lower than at baseline at 5 to 6 weeks (P = .0025), After the second injection, mean pressure was 2.6 mm Hg lower at 2 to 3 weeks (P = .0013) and 1.5 mm Hg lower at 5 to 6 weeks (P = . 043). After subsequent injections, however, the decrease was less than 1 mm Hg, suggesting that a plateau had been reached, Pressure in eyes with anterior uveitis after the first injection was lower than that i n eyes without anterior uveitis (P < .0001). The mean rate of aqueous flow decreased from 2.8 to 1.9 mu l per minute 2 to 4 weeks after inje ction (P <.015). Ultrasound biomicroscopy disclosed that severe hypoto ny after cidofovir injections is associated with ciliary body atrophy. CONCLUSIONS: Intraocular pressure decreases after the initial 20-mu g cidofovir intravitreal injection, However, eyes stabilize (pressure p lateaus) after three injections. Effects on the ciliary body are the m ain cause of the decrease after cidofovir injections.