Interferon and Ocular Viral Disease

The eye has received considerable attention in the study and evaluation of the effect of interferon and interferon inducers on viral disease. Since this organ is easily visualized, permits easy access to culture material, is frequently involved in viral infections, and can be studied under intense magnification in the in vivo state, it is a logical organ system for such study. Furthermore, most ocular diseases can be treated topically, and the effects of therapy with interferon and/or interferon inducers may be studied without some of the problems encountered in evaluating the influence of systemic therapy on local organ disease. In 1960, Cantell and Tommila reported on the effects of exogenous interferon on vaccinia keratitis. They noted that the external application of interferon, derived from rabbit kidney cells, to rabbit eyes for 4 days after corneal inoculation of vaccinia virus delayed and suppressed the signs of infection (1). These same investigators also noted that a similar course of treatment did not influence herpes simplex virus infection of rabbit corneas. Jones et al. treated five cases of human epithelial vaccinia keratitis with topical monkey interferon applied every 12 hr during the patient's waking hours (2). They noted that topical interferon appeared to have a specific antiviral effect on the epithelial stages of the disease, and that if stromal involvement had occurred, these changes were not altered. Rapid healing of the epithelial infection was noted, and it was clear that in no instance was there worsening of the epithelial lesions once interferon was administered. Tommila and Penttinen attempted to determine why herpes simplex viruses had proved to be relatively insensitive to interferon applied to rabbit eyes in vivo as well as in tissue culture (3). They reasoned that the failure of exogenously applied interferon might be due to the low interferon content of the administered material, as well as to insufficient application of the preparation used. They endeavored to produce a high interferon concentration in the eye by applying the virus that had been utilized in the preparation of interferon in vitro directly to the eye. A study was undertaken, therefore, to determine the effect of ultraviolet irradiated influenza type B,