Aims-To determine the sensitivity and specificity of culture, immunohistoch
emistry (IHC), the polymerase chain reaction (PCR), and in situ hybridisati
on (ISH) for detecting herpes simplex virus (HSV-I) in the cornea of patien
ts undergoing penetrating keratoplasty. To compare the incidence of HSV-1 i
n the cornea with that of varicella tester virus (VZV), cytomegalovirus (CM
V), and Epstein-Barr virus (EBV).
Methods-The corneas of 110 patients, 52 with a documented history of herpes
keratitis (HSK) and 58 with non-herpetic corneal disease, were investigate
d using IHC, PCR, ISH, and culture.
Results-HSV-1 DNA and antigen were detected in 82% and 74% respectively, of
corneas of patients with HSK and in 22% and 15% of corneas of patients wit
h no history of HSK. The sensitivity of PCR and IHC was 82% and 74% with a
specificity of 78% and 85%, respectively. HSV-1 DNA and antigen were found
more frequently and in increased amounts in corneas of patients with a shor
t interval between their last attack of HSK and surgery. There was a good c
orrelation between PCR and IHC in 71%. HSV-1 was isolated by culture in 2%.
Latency associated transcripts were not detected using ISH. Evidence of VZ
V DNA or antigen was found significantly more frequently in the corneas of
patients with a history of HSK (p<0.001). No evidence of EBV or CMV was fou
nd in any cornea.
Conclusions-PCR and IHC are both sensitive for the detection of HSV-1 in th
e cornea. A combination of PCR and IHC increases the specificity for the di
agnosis of HSK to 97%. HSV-1. appears to be slowly removed from the cornea.
VZV and HSV-1 may co-infect the cornea.