Quantitative analyses of cytomegalovirus genome in aqueous humor of patients with cytomegalovirus retinitis

PURPOSE: To investigate copy numbers of cytomegalovirus (CMV) in CMV retinitis patients during ganciclovir treatment using real-time polymerase chain reaction (PCR). METHODS: Thirteen aqueous humor samples obtained from 6 patients with clinically diagnosed CMV retinitis were analyzed. As controls, aqueous humor samples were obtained at the time of surgery from patients with senile cataracts. RESULTS: The CMV genome was detected in the range from 10(1) to 10(4) copies/microL of aqueous humor before antiviral treatment. The samples obtained from retinitis patients showing widespread retinal changes contained much higher copy numbers than those from patients with focal lesions. After treatment, the copy number decreased to one hundredth of that observed prior to treatment, but the CMV genome was detectable for 4 to 8 weeks after ganciclovir administration to 4 patients. CONCLUSION: These results revealed the correlation between the copy numbers of the CMV genome and the extent of the area affected by CMV retinitis before antiviral treatment, and the prolonged retention of CMV genome after antiviral treatment. Quantitation of the viral genome after the start of therapy will be of value in determining whether to continue or intensify the dosage of antiviral agents.