Abstract
Purpose::
Herpes viruses can induce a variety of corneal disorders, leading to corneal transplantation in a lot of patients. Recent studies suggest polymerase chain reaction (PCR) the method of choice to detect viral DNA in ocular specimens. In view of a treatable disease, we analyzed Herpes virus DNA in ocular specimens at time of keratoplasty.
Methods::
In the time period from 1.12.1998 to 31.12.2003 aqueous humour (AH) and/or a quarter of the recipient corneal button (CO) were analyzed for HSV-DNA and VZV-DNA by PCR technique in a prospective study at a single university center.
Results::
During the study 769 keratoplasties were performed in 530 patients (median age: 73y, range 0-95y; gender: 55% female; 108 patients were analyzed at least at two or more different occasions). In 34 cases (4.4%) no PCR test was performed. PCR reaction rarely showed inhibitory substances (HSV-AH 14x, VZV-AH 9x, HSV-CO 13x, VZV-CO 6x). The majority of specimens were negative for HSV and VZV in AH and CO (580 cases, 75.4%). Positive results were found for HSV more frequently than for VZV (HSV-AH 34x, VZV-AH 1x, HSV-CO 36x, VZV-CO 2x). Concomitant positive results for HSV and VZV were never found in AH or CO; HSV-PCR simultaneously positive in AH and CO was tested 14x. Herpes virus PCR was found in Fuchs dystrophy 2.2% (n=175), Keratoconus 2.1% (n=140), corneal inflammation or scar typical or suspective for Herpes keratitis 17% (n=135), bullous keratopathy 5.4% (n=55).
Conclusions::
Herpes virus DNA can be found in about a quarter of ocular specimens at time of keratoplasty. The proportion of positive results in suspected ocular Herpes is lower than expected, positive results are more probable if cornea and aqueous humour are analyzed. PCR testing cannot replace intensive clinical workup.
Keywords: cornea: clinical science • herpes simplex virus • varicella zoster virus