Scanning Electron Microscopic Observations of Sequential Alterations of Type 1 HSV Keratitis in Rabbits

ABSTRACT

PURPOSE: This study aimed to investigate the microscopic findings of characteristic epithelial herpes simplex keratitis (HSK) and the changes of those findings over time. METHODS: Sixteen rabbits were inoculated with the Kos-stain of herpes simplex virus (HSV) type 1 in both eyes. Two rabbits each were enucleated on the 2nd, 3rd, 4th, 5th, 6th, 7th, and 9th day after viral inoculation and were observed with a scanning electron microscope (S-2380n, Hitachi, Japan). RESULTS: Corneas showed dendritic epithelial desquamation, changes in epithelial microvilli, and changes in intercellular adhesion. With progression, the basement membrane and basal cells were exposed, intercellular spaces were broadened, and the adhesion of basal cells to basement membrane and the intercellular adhesion were loosened. Later, infiltrations of some inflammatory cells were found. Until the last day there was no destruction of basement membrane or an exposure of stroma. CONCLUSIONS: Though it was impossible to follow up a lesion throughout the experiment because of the necessity of enucleation, and in addition, the findings could not be generalized to all the strains, this study provides a better understanding of HSK. Further studies on various manifestations of HSK from other strains of HSV are needed in the future.