Identification of cytomegalovirus in vitreous using the polymerase chain reaction*

A presumptive clinical diagnosis of cytomegalovirus (CMV) retinitis was made in two patients presenting with atypical ophthalmologic findings. The diagnosis was confirmed by finding specific CMV DNA sequences in sampled vitreous fluid using a polymerase chain reaction (PCR) based assay. Neither of these patients yielded CMV on culture or PCR of peripheral blood leucocytes, nor was CMV present in tears or urine of either patient. Serum antibody titres were stable and did not help in establishing the diagnosis. This report suggests that CMV retinitis can occur in the absence of disseminated CMV disease.