Diagnostic and therapeutic results of aqueous real-time polymerase chain reaction in infectious uveitis

Objective: This study was aimed primarily at describing the results of aqueous real-time polymerase chain reaction (RT-PCR) and reporting the rate of therapeutic modifications directly attributable to this procedure (profitability). Our secondary outcome was to compare demographic and clinical characteristics between patients with RT-PCR positivity and those with RT-PCR negative results. Design: Retrospective observational study conducted at the Uveitis Service of San Raffaele Hospital (Milan, Italy) between November 2016 and July 2022. Participants: Patients with infectious uveitis suspect (anterior, intermediate, posterior uveitis, or panuveitis). Methods: Patients with suspected infectious uveitis underwent aqueous RT-PCR for detection of herpes simplex 1 (HSV-1), herpes simplex 2 (HSV-2), varicella zoster virus (VZV), cytomegalovirus (CMV), and Toxoplasma gondii. Results: Sixty-five eyes of 61 patients (60 ±16 years of age; 54% males) were included. Aqueous RT-PCR tested positive in 58% and negative in 42% of patients. CMV and HSV-1 were the most frequently detected pathogens. RT-PCR confirmed clinical suspicion in 38% of patients and altered the presumed etiologic diagnosis and treatment in 20% of patients. Profitability was associated with CMV positivity. HSV-1 positivity was related to iris atrophy. CMV positivity was correlated with keratic precipitates. Vitritis and retinitis were related to VZV, CMV, and T. gondii detection. Synechiae, retinitis, and neuritis were related to positive tests regardless of the pathogen investigated. Early complications related to paracentesis were rarely reported. Conclusion: Aqueous RT-PCR was a safe semi-invasive tool to confirm a presumptive diagnosis and to change initial suspicion in ambiguous cases of herpetic uveitis. Thus aqueous RT-PCR may alter therapeutic management.