Cytomegalovirus (CMV) retinitis activity is accurately reflected by the presence and level of CMV DNA in aqueous humor and vitreous.

To evaluate the potential of ocular and systemic specimens to provide markers of active cytomegalovirus (CMV) retinitis, we examined the relationship between virologic and clinical aspects of CMV infections in AIDS patients with CMV retinitis. CMV polymerase chain reaction (PCR) analysis of 74 aqueous humor and vitreous specimens indicated that ocular specimens can provide accurate markers to differentiate active and inactive CMV retinitis (aqueous or vitreous PCR, P<.001). Moreover, these markers were superior to extraocular measures, including plasma PCR (P=.08) and blood and urine CMV cultures (P=.05). A direct correlation was identified between the quantity of CMV DNA in aqueous humor or vitreous specimens and the corresponding surface area of active CMV retinitis (r2=.69 and.44, respectively). Thus, qualitative and quantitative PCR-based analyses of aqueous humor can provide valuable markers of CMV retinitis activity. Such assays could provide rapid and reliable tools to assist in management of patients with CMV retinitis in whom the view of the retina is obscured.