Detection of herpes simplex virus DNA in atypical epithelial keratitis using polymerase chain reaction

Aim-To study herpes simplex virus (HSV) DNA in tears from patients with aty pical epithelial keratitis of unknown aetiology. Methods-Tear samples were collected from 17 affected eyes of 17 consecutive patients suffering from epithelial keratitis in whom HSV keratitis was sus pected but whose diagnosis was difficult on the basis of clinical manifesta tions alone. Using reduced sensitivity polymerase chain reaction (PCR), tea r samples were tested for HSV DNA. Tears from the unaffected eyes of the 17 patients were also examined, along with 38 tear samples from 19 normal vol unteers. Southern blot analysis was performed to confirm that amplified DNA bands were specific for HSV. Clinical correlation with photographs of corn eal lesions was also investigated. Results-HSV DNA was detected in tears from the affected eyes of eight of th e 17 patients with suspected HSV keratitis. Tears from the affected eyes of the other patients were PCR negative, as were tears from the unaffected ey es of all 17 patients, and from the 38 normal eyes. There was no correlatio n between PCR results and clinical manifestation of keratitis. Conclusions-Based on the sensitivity of the PCR system, eight of 17 suspect ed HSV keratitis patients were confirmed as suffering from HSV keratitis. H SV keratitis should therefore be considered as a possible diagnosis in atyp ical epithelial keratitis.