Abstract
Purpose::
Healing time in ocular herpes keratitis has historically been assumed to correspond with virus activity. In the past, demonstrating the presence of ocular Human Herpes Virus Type 1 (HSV-1) without the use of stains for mild epithelial disruption has been without a solution. Moreover, the ability to observe actual HSV-1 on the epithelium or within the stroma of the in situ cornea has been a frank impossibility. Our purpose was to observe the correlation between the presence of the virus and the defect in the epithelium it produces, and the corneal healing as the virus disappears.
Methods::
Animals were handled according to the ARVO Statement on the Use of Animals in Ophthalmic and Vision Research and the NIH Guidelines on the Care and Use of Animals in Research. New Zealand white rabbits were infected with the KOS/EGFP strain of HSV-1 OD and OS. Animals were inspected on the first day post infection via fluorescent microscopy for viral identification and slit lamp examination with fluorescein and cobalt blue filter to establish clinical disease. Photos obtained from these examinations were analyzed by conversion to grayscale, and subsequent color threshold changes allowed us to compare viral activity to epithelial healing.
Results::
Preliminary results indicate that clinical disease correlates directly with viral activity on/within the cornea. Invariably, virus appears days before the first noticeable clinical effect can be distinguished. We were able to discern a similar pattern upon the conclusion of viral activity and the correlating end of clinical disease being separated by a few days.
Conclusions::
Our results give substance to previous thoughts on HSV keratitis disease course. It is now evident that viral activity has a strong correlation with epithelial disease in HSV keratitis. This model of herpes keratitis may permit us to make better decisions of when to cease treatments and possibly avoid cytotoxicity from current treatment regimens.
Keywords: herpes simplex virus • keratitis