According to a recent British study, the herpes simplex virus (HSV-1) can be detected in the cornea with the use of polymerase chain reaction (PCR) and in situ hybridisation (ISH).

The corneas of 110 patients -- 52 with a documented history of herpes keratitis (HSK) and 52 with non-herpetic corneal disease -- were investigated using immunohistochemistry (IHC), PCR, ISH and culture.

HSV-1 DNA and antigen were detected in 82% and 74%, respectively, of the corneas of patients with HSK, and in 22% and 15% of corneas of patients with no history of HSK. PCR and IHC sensitivity was 82% and 74% with a specificity of 78% and 85%, respectively.

Researchers concluded that the specificity for the diagnosis of HSK could be increased to 97% by using a combination of PCR and IHC.