PCR in posterior segment viral diseases

Abstract

AbstractSince its introduction in the early eighties, PCR has dramatically changed our approach to the diagnosis and understanding of intraocular viral diseases. Even though serology remains the effective diagnostic tool for diseases such as West‐Nile virus or dengue‐virus retinitis, PCR is the gold‐standard for herpetic retinopathies. Two major subtypes have been described including necrotizing and nonnecrotizing herpetic retinopathies. In Europe, diagnosis is performed based on the analysis of the aqueous humor, whereas vitrectomy is more frequently performed in the USA. Less than 100 microlitters of liquid is sufficient for the procedure. Real‐time PCR is now available for most of the herpesviruses allowing a quantitative determination of the viral load. The identification of the viral agent is paramount in the management of the disease by adapting the antiviral strategy. VZV, HSV‐1, HSV‐2 and CMV are the main causes of viral retinitis. Acute retinal necrosis syndrome is mainly observed in immunocompetent patients whereas, progressive outer retinal necrosis syndrome and CMV retinitis occur classically in immunocompromised patients. Intravitreal injection of corticosteroids must be considered as a risk factor. The decrease of the viral load is a major prognostic factor and must be taken into consideration for an optimal management.