DETECTION OF HERPES-SIMPLEX VIRUS-DNA IN TEAR FLUID OF STROMAL HERPETIC-KERATITIS PATIENTS BY NESTED POLYMERASE CHAIN-REACTION

The value of the polymerase chain reaction (PCR) in the diagnosis of s tromal herpetic keratitis was examined using tear fluid specimens; the sensitivity of the nested PCR method in detecting the herpes simplex virus (HSV) genome was 1 plaque-forming unit/mL. PCR assay of 72 tear samples from the eyes of 15 patients with stromal herpetic keratitis d etected the HSV genome in 5 (33.3%). No positive band was detected in 20 tear samples from both eyes of 10 healthy volunteers. Seven of 38 t ear samples (18.4%) and 1 of 34 samples (2.9%) collected from the dise ased eye and the contralateral normal eye, respectively, produced posi tive results; the difference in rates was statistically significant (P <0.05). The positive rate of samples collected from the diseased eye during an active phase was 16.0% (4 of 25 samples); in the quiescent p hase, 23.1% (3 of 13 samples); the difference was not significant (P=0 .45). In HSV genome-positive cases, the average number of tear collect ions needed to detect the HSV genome was 3.3. Results indicate that PC R assay of tear fluid provides valuable information for the diagnosis of stromal herpetic keratitis, and that repeated tear samples should b e collected regardless of the phase of disease activity.