Ocular Herpes Simplex Infections

Abstract

Not surprisingly, ocular herpes simplex infec­ tions seem enigmatic to the nonophthalmologic physician in comparison with the stereotyped course of other types of mucocutaneous herpes simplex infections. In general terms, the major affliction of nonocular mucocutaneous disease— for example, herpes genitalis and herpes labialis—is frequent recurrence of painful cutaneous disease that is not amenable to topical antiviral therapy. These infectious episodes are generally self-limited and rarely cause structural altera­ tions in affected tissues. In contrast, ocular herpes simplex infections are less likely to recur but may result in chronic inflammatory disease of the cornea, an avascular, transparent structure that serves as an interface between the external ocular environment and the receptive visual neurosensory tissues of the eye. Consequently, although frequent painful erup­ tions are the major source of morbidity in pa­ tients with herpes genitalis or labialis, ocular herpes simplex is less a problem of recurrence than of structural alterations of the eye and secondary loss of vision. One can contrast the reported rates of recurrence of genital herpes simplex virus type 2 of 0.33 per month (in 24 of 27 patients or 89%) and orolabial herpes simplex virus type 1 infections of 0.12 per month (in 5 of 12 patients or 42%) in one study1 with the 40% ocular recurrence rate during a 5-year period for patients with corneal epithelial herpetic kerati­ tis. 2 Multiple recurrences are thus more common with genital or oral herpes in contrast with iso­ lated or infrequent recurrences of ocular herpes simplex. The major complications of ocular herpes simplex occur in deep herpetic corneal and intra­ ocular inflammatory infections that may have a tendency toward chronicity, result in loss of vision, and, in a small subpopulation of pa­ tients, necessitate surgical rehabilitation. In the