Detection of HSV nucleic acid sequences in the cornea during acute and latent ocular disease

This study evaluated the continued presence of herpes simplex virus (HSV) nucleic acid sequences after resolution of acute herpetic stromal keratitis in the rabbit ocular model. Forty-four rabbits were inoculated bilaterally with 10(5) plaque-forming units of RE strain HSV-1 by intrastromal injection. All eyes were cultured for the presence of HSV during acute disease and immediately before the animals were killed. Full-thickness corneal buttons were then removed and processed for in situ hybridization with a 3H-labelled HSV DNA probe representing the full-length HSV genome. HSV nucleic acid sequences were detected autoradiographically at all time intervals examined. HSV nucleic acid sequences were localized in the epithelium and the anterior stromal keratocytes during acute disease and in all corneal layers during latent infection. Retention of HSV nucleic acid sequences, either HSV DNA or HSV RNA, or both, in corneal tissues (epithelium, stroma, and endothelium) may be a contributing factor in the development of HSV-induced stromal keratitis.