Cytomegalovirus retinitis in patients with AIDS: current status.

About 20%-30% of patients with AIDS will develop cytomegalovirus (CMV) retinitis when they are severely immunodeficient (CD4 cell count below 40 cells/microL). It causes extensive retinal damage with visual deficits, and relapses are frequent. Intravenous ganciclovir and foscarnet are standard therapy, but their high toxicity and long term intravenous access mean that advances in treatment, including oral prophylactic agents, intravitreal injections and surgical implants, may provide a better quality of life for patients. Prophylactic ophthalmological screening of patients with CD4 cell counts below 100 cells/microL to detect asymptomatic retinitis is needed.