Purpose:
The herpes virus simplex types 1 (HSV-1) and 2 (HSV-2), and varicella zoster virus (VZV) are important causes of corneal blindness, becoming essential the early diagnosis and prompt initiation of appropriate therapy in order to reduce disease morbidity. In this sense, the real-time polymerase chain reaction (real-time PCR) is considered an important diagnostic method of herpetic eye diseases because of its high sensitivity and relatively rapid processing time. The purpose of this trial is to develop a real-time PCR assay to detect HSV-1, HSV-2 and VZV in corneal scrapings from patients who presented clinical suspicion of herpes keratitis (dendritic or geographic ulcers).
Methods:
Patients admitted at the Ophthalmology Department were enrolled in this study, and the cases clinically diagnosed as herpes were submitted to sample collection. DNA was extracted from samples using a QIAamp DNA Mini Kit and the real-time PCR assay was carried out with a TaqMan universal PCR mix in the ABIPrism 7500 equipment.
Results:
Among the 25 patients elegible during the period of study, 17 (68%) were males and 8 (32%) were females and the mean age was 47,8 years (17-84 years). In the case of typical herpes ulceration, 21/25 of samples were positive for HSV-1, corresponding to a positive predictive value of 84%.
Conclusions:
These results confirm the high sensitivity of real-time PCR for the diagnosis of herpes keratitis. The introduction of the real-time PCR assay represents a valuable tool in cases of unknown etiology.
Keywords: herpes simplex virus • keratitis • detection