The coincidence of HSV-1 ocular cultures with HSV-1 corneal epithelial defects in rabbits after experimental penetrating keratoplasty.

Penetrating keratoplasty (PKP) in conjunction with postoperative corticosteroids may reactivate latent herpes simplex virus type 1 (HSV-1) to cause persistent postoperative epithelial defects. The clinical diagnosis of HSV keratitis after penetrating keratoplasty is difficult because the postoperative appearance may be nondendritic and, therefore, not characteristic of HSV-1 infection. Presently, the most reliable method to diagnose HSV-1 under these conditions is to culture eyes for the presence of HSV-1. To determine the coincidence of positive HSV-1 ocular cultures with HSV-1 epithelial defects, 15 rabbits (20 eyes) latently infected with HSV-1 underwent autograft PKP with postoperative corticosteroids. Daily ocular cultures and slit-lamp examinations were performed on postoperative days 1-8 and 10. Viral shedding occurred in 15 of 19 (79.0%) of the eyes postoperatively. Superficial punctate keratopathy (SPK) was observed in 19 of 19 (100%) of the eyes and coincided with positive HSV-1 cultures 24% of the time. Dendritic lesions were observed in three of 19 (15.8%) of the eyes; the dendrites coincided with positive HSV-1 cultures 60% of the time. Finally, epithelial ulcers were seen in eleven of 19 (57.9%) of the eyes, thus coinciding with HSV-1 positive cultures 29% of the time. The greatest coincidence of positive HSV-1 cultures with nondendritic epithelial lesions occurred on postoperative day number 4. The results suggest that an epithelial lesion following PKP and postoperative corticosteroids could represent HSV infection, even if a single HSV ocular culture is negative.