Incidence of cytomegalovirus (CMV) retinitis in second eyes of patients with the acquired immune deficiency syndrome and unilateral CMV retinitis

PURPOSE: To evaluate the risk and risk factors for developing cytomegalovirus (CMV) retinitis in previously uninvolved second eyes among patients with unilateral CMV retinitis. DESIGN: Cohort study. METHODS: SETTINGS: Single-center academic AIDS ophthalmology practice. PATIENT POPULATION: Three hundred seventy-six consecutive patients with AIDS and unilateral CMV retinitis were followed from the time of CMV retinitis diagnosis for the development of second-eye retinitis. EXPERIMENTAL PROCEDURES: Demographic and clinical characteristics were noted at baseline. Use of highly active antiretroviral therapy (HAART) and immune recovery in response to HAART were noted prospectively. MAIN OUTCOME MEASURE: Development of CMV retinitis in a previously uninvolved eye. RESULTS: Ninety-one percent of subjects received systemic anti-CMV treatment. Second-eye retinitis occurred in 26.1%/person-year (19.6% within the first 6 months), less than half the rate previously reported in untreated groups. Initial CD4+ T cell count >12 cells/microl, use of HAART, and initial posterior pole involvement were associated with 64%, 46%, and 41% reductions in incidence vis-à-vis comparison groups. Benefit from HAART was limited to that subset who developed immune recovery of a degree expected to restore innate control of CMV (a rise in the CD4+ T cell count by >50 cells/microl to a level >100 cells/microl). CONCLUSIONS: The risk of second-eye retinitis is substantial in patients with unilateral CMV retinitis but appears to be reduced by anti-CMV therapy and by HAART-induced immune recovery. Patients are at highest risk when CD4+ T cell counts are very low and in the months immediately after CMV retinitis diagnosis.