Detection of human cytomegalovirus in ocular tissue by polymerase chain reaction and in situ DNA hybridization.

Rapid and sensitive techniques with a high degree of accuracy are necessary for the diagnosis and management of cytomegalovirus (CMV) retinitis presenting with atypical clinical manifestations. Light microscopy and immunohistochemical studies have limitations in the identification of this virus, but in situ DNA hybridization offers a rapid, highly specific, and easily interpretable means of identifying CMV. A new procedure of enzymatic amplification of DNA in vitro, called the polymerase chain reaction (PCR), has yielded excellent results in the identification of various viruses. In the study described herein, we evaluated the diagnostic usefulness of PCR and compared its reliability with that of in situ DNA hybridization for the detection of CMV in ocular tissues. We found that the reliability of the PCR method is similar to in situ DNA hybridization for the detection of CMV, although morphologic correlation is provided only by the latter technique. False-negative results can occur in PCR if the correct primer is not used.