The Efficacy of Two Potential Diagnostic Assays for Herpes Simplex Keratitis (HSK)

The aim of this study is to compare the safety, specificity, sensitivity and ease of procedure of two potential diagnostic assays for HSV-1 detection in the cornea. Through the use of this new diagnostic assay, correct and early intervention would not only reduce corneal scarring from HSK, but it would also allow the initiation of appropriate treatment for HSV mimicking keratitis.

HSV-1 infection of the eye can result in corneal scarring and blindness. Early diagnosis of this condition and appropriate treatment is of utmost importance. Various ocular surface conditions can mimic herpetic keratitis in their clinical presentation and can result in diagnostic confusion. Inappropriate or delayed treatment of herpetic corneal disease results in increased morbidity.

In the UK at present clinical presentation is the mainstay of diagnosis. Unfortunately these cases often present to the most inexperienced clinical staff resulting in variability in diagnostic acumen. This often results in a delay or inappropriate diagnosis of herpetic keratitis. Laboratory techniques presently available to aid diagnosis are infrequently used in clinical practice. There are various reasons for their lack of use. Historically viral culture techniques were the mainstay of investigation but were slow, requiring weeks to provide a result. PCR is now replacing culture techniques and is relatively quick, reliable and sensitive. Many clinicians within the UK are still not fully informed of these advances and are therefore not utilizing these techniques to supplement clinical diagnosis.

We propose to investigate the use of topically applied fluorescent antibody against active replicating HSV-1 in a droplet form and real time PCR detection of the virus. If successful this should increase the potential diagnostic capabilities of GPs and other less experienced health care workers. Such tests should reduce variability in diagnosis and the dependency on experienced ophthalmologists to diagnose the condition.