Presence of a Large Amount of Herpes Simplex Virus Genome in Tear Fluid of Herpetic Stromal Keratitis and Persistent Epithelial Defect Patients

Herpetic eye diseases exhibit various clinical manifestations making a diagnosis difficult in some patients. We quantitated herpes simplex virus (HSV) genomes in the tear fluid and aqueous humor obtained from patients with various herpetic eye diseases by real time PCR. The resulting amounts of HSV-DNA in herpetic epithelial keratitis (HEK), herpetic stromal keratitis (HSK) in active phase, and persistent epithelial defects (PED) were 3.9 × 106 copies (detection rate, 81.1%), 8.9 × 105 copies (detection rate, 59.1%), and 9.2 × 104 copies (detection rate, 88.9%), respectively. In the tear samples obtained from quiescent phase of HSK and endotheliitis, no HSV-DNA was detected. In the aqueous humor of uveitis patients, HSV-DNA was found 3.8 × 105 copies/ml (detection rate, 16.7%). Previous studies have shown that active viral replication is not directly related to the persistent epithelial defects and progressive HSK. A relatively high level of HSV-DNA, however, was detected in the tear samples of these two disease forms, although the source of the viral replication was not identified. These findings might bring new ideas about the mechanisms of developments in HSK and PED.