Visual field loss in patients with cytomegalovirus retinitis

Abstract

Purpose: To describe visual field (VF) loss among patients with cytomegalovirus (CMV) retinitis and the risk factors for such loss.

Design: Multicenter, prospective, observational study.

Participants: A total of 476 patients with AIDS and CMV retinitis, and VF data.

Methods: Follow-up every 3 months with medical history, ophthalmologic examination, Goldmann visual fields, and laboratory testing.

Main outcome measures: Incidence of VF loss in eyes affected with CMV retinitis and characteristics associated with such VF loss.

Results: Over a median follow-up of 4 years (range, 0.5-9 years), the incidence rates of VF loss to 75% and 50% of normal were 0.22/eye-year (EY, 95% confidence interval [CI], 0.20-0.25) and 0.08/EY (95% CI, 0.06-0.10), respectively. The observed rates were 6- to 7-fold less than those observed rates of VF loss in the era before highly active antiretroviral therapy (HAART). Decreased CD4+ T-cell count, whether measured at enrollment or over follow-up time, was associated with increased rates of VF loss for all VF outcomes in a dose-dependent fashion. Risk factors for VF loss included lower CD4+ T-cell count, CMV lesion size >25% of the total retinal area, and active CMV retinitis after controlling for potential confounding. Highly active antiretroviral therapy use and immune recovery (CD4+ T-cell count >100 cells/μL) were associated with reduced risk of VF loss in multiple regression models. Immune recovery was statistically significantly associated with a lower risk of VF loss to 75% of normal (relative risk [RR] = 0.63; 95% CI, 0.49-0.86; P = 0.003) and to 50% of normal (RR = 0.60; 95% CI, 0.44-0.82; P = 0.001) after controlling for demographic characteristics, HIV viral load, HAART use, CMV lesion location and size, and retinitis activity.

Conclusions: Cytomegalovirus retinitis was associated with a substantial risk of incident VF loss, but the incidence is approximately 6-fold lower than that observed in the pre-HAART era. Those who have HAART-induced immune recovery have approximately 40% lower risk of VF loss for both outcomes after controlling for confounding.