DETECTING HERPESVIRUS DNA IN UVEITIS USING THE POLYMERASE CHAIN-REACTION

Background-Herpesviruses are involved in the pathogenesis of many ocul ar diseases including keratitis, iridocyclitis, and acute retinal necr osis syndrome. The rapid and accurate diagnosis of herpetic infections has become increasingly important with the rising incidence of immuno suppressive diseases. The purpose of this study was to evaluate the us e of the polymerase chain reaction (PCR) to detect herpesvirus DNA in uveitis patients. Methods-Aqueous samples were aspirated from 11 patie nts with active uveitis of suspected viral origin. Using PCR, masked s amples were assayed for herpes simplex virus (HSV), varicella tester v irus (VZV), and cytomegalovirus (CMV) to assist in supporting the clin ical diagnosis of viral aetiology. Masked controls included 10 aqueous humour specimens from normal patients undergoing cataract surgery and specimens from seven patients diagnosed with active non-viral uveitis - Behcet's disease, sarcoidosis, Fuchs' heterochromic iridocyclitis, or Harada's disease. Results-Ten of 11 cases clinically diagnosed as b eing of possible viral aetiology yielded aqueous PCR positive for a he rpesvirus. Eight patients were PCR positive for amplified HSV DNA, of whom two had acute retinal necrosis, one had corneal endotheliitis, an d five had recurrent iridocyclitis. VZV DNA was detected in one case o f iridocyclitis, and CMV DNA in one case of chorioretinitis. Successfu l therapy was based on the PCR results. Ten normal aqueous specimens a nd the seven uveitis samples from cases not suspected of a viral aetio logy were PCR negative for HSV, VZV, and CMV. Conclusion-These results demonstrate that detecting herpesvirus DNA in the aqueous humour is u seful to support a clinical diagnosis of viral uveitis.