Iatrogenic risk factors for cytomegalovirus retinitis.

Background: To determine the iatrogenic risk factors for cytomegalovirus (CMV) retinitis in patients with the acquired immunodeficiency syndrome (AIDS).

Methods: The case-control study included 120 patients with CMV retinitis and 159 patients without CMV retinitis, all of whom had AIDS and CD4 counts less than 50 cells/microL at the time of diagnosis of retinitis or at the defined corresponding date in the controls. Iatrogenic risk factors studied were corticosteroid use, treatment with chemotherapy, treatment with radiotherapy, and blood transfusions.