Herpes simplex virus DNA in corneal transplants: prospective study of 38 recipients

Herpes simplex virus (HSV) infection of the eye can induce epithelial and stromal keratitis and may also lead to postoperative endothelial failure in keratoplasty. Clinical symptoms and/or virus culture of corneal scrapings most frequently provide the basis for diagnosis of ocular HSV infection, and although HSV DNA has been shown to be present in the cornea, its role in success or failure of corneal grafts remains unclear. In this study, a PCR assay was used to detect HSV DNA in corneal buttons of 38 corneal graft recipients and in donor scleral remnants, retaining one-half of each sample for subsequent viral isolation. Recipients were followed up clinically for a period of 6 months after keratoplasty. All recipients but three were found to be HSV seropositive. Eight recipient corneal buttons contained detectable HSV DNA (7 HSV-1, 1 HSV-2, the latter case confirmed by viral culture). Two donor corneas were found positive for HSV-1 DNA, with negative cultures, and endothelial graft failure occurred in one of the matching recipients after 4 months. One recipient with no history of herpes contracted herpetic keratitis 4 months after keratoplasty, even though the corneal button and donor scleral remnants contained no detectable HSV DNA. The study confirms previous observations of HSV DNA in the corneal tissue of HSV seropositive patients apparently unrelated to any clinical manifestation of herpes infection. However, as demonstrated by culture, HSV remains infectious and may therefore induce donor-to-host infection in corneal recipients.