Role of PCR in Diagnosis and Management of Infectious Uveitis

Abstract

Abstract: : Purpose: To analyze the value of laboratory tests applied to ocular fluids for the diagnosis of infectious uveitis. Methods: Prospective review of clinical records, etiological orientation and therapeutic outcome of new patients referred to the department of Ophthalmology for a suspicion of infectious uveitis between January and December 2001. Different serologies were performed based on clinical presentations. Ocular fluids were obtained in atypical cases in order to confirm initial orientations. PCR and analysis of specific intraocular antibody production (SIAP) were associated to improve etiological confirmation. Results: Among 671 patients included in this prospective study, an infectious condition was identified in 188 cases (28%). Retinochoroidal toxoplasmosis was the most frequent condition (67 cases) followed by herpetic infections (51 cases), bacterial infections (53 cases) and candidiasis (6 cases). Analysis of ocular fluids was contributive in 87% of atypical or extensive toxoplasmosis, 45% of atypical anterior herpetic uveitis, 83% of necrotizing viral retinopathies, 14.6% of bacterial uveitis, 58% of acute endophthalmitis and 16.6% of ocular candidiasis. PCR was highly informative in patients presenting with a viral condition whereas SIAP was more contributive during toxoplasmosis. This diagnostic procedure allowed us to confirm 7 cases of non necrotizing herpetic retinopathies and CMV–associated uveitis, two recently reported infectious entities. PCR analysis was repeated during the therapeutic management of herpetic retinopathies in order to confirm the absence of viral replication, before the adjunction of corticosteroids. Conclusions: Diagnostic management of infectious uveitis remains a major challenge for ophthalmologists. New entities may be identified among patients with a previous diagnosis of idiopathic uveitis. PCR and serologic analysis of ocular fluids may be proposed in atypical forms of severe, chronic and sight–threatening uveitis, in order to avoid the use of aggressive or non conventional immunosuppressors and to propose a specific therapeutic strategy.

Keywords: clinical laboratory testing • toxoplasmosis • uveitis-clinical/animal model