Polymerase chain reaction to search for Herpes viruses in uveitic and healthy eyes: a South African perspective.

OBJECTIVE To analyse aqueous polymerase chain reaction (PCR) results in patients diagnosed with undifferentiated uveitis and determine prevalence of herpesviridae in non-uveitic patients undergoing routine cataract extraction. DESIGN Retrospective comparative case series and prospective cross-sectional study. SUBJECTS 72 patients with idiopathic uveitis and 57 surgical patients. METHODS Diagnostic aqueous paracentesis with PCR testing for 6 herpes viridae in uveitic patients. Anterior chamber paracentesis immediately pre-operative in the prospective arm, with PCR testing. RESULTS In the retrospective review we had a 47.2% positive PCR yield. Data analysis revealed a statistically significant correlation between a positive yield and being HIV+ (p=0.018); between an EBV+ yield and being HIV+ (p= 0.026) and a CMV+ result and being HIV+ (p=0.032). Posterior uveitis (p=0.014) and symptoms <30 days (p= 0.0014) had a statistically significant yield. In the prospective arm of the study: all 57 patients were HIV- and all aqueous samples were negative for the 6 herpesviridae. CONCLUSION We recommend PCR testing for Herpesviridae as a safe second line test for patients with undifferentiated uveitis. We were unable to establish prevalence and suggest that the idea of a commensal herpes virus is unlikely if the blood-ocular barrier is intact.