Herpetic Eye Disease Study (HEDS) I

Herpes simplex keratitis is a leading cause of corneal opacification in the United States, other industrialized countries, and developing nations throughout the world. An estimated 450,000 people in the United States can develop recurrent episodes of the disease and about 46,000 episodes of HSV eye infection every year. Herpetic eye disease is the most common infectious cause of corneal blindness in this country.

Despite the availability of antiviral agents that are effective in treating herpes simplex epithelial keratitis, inflammation in the corneal connective tissue and iris that can lead to corneal scarring and visual impairment develops in many patients. Prior to the HEDS-I trials, the role of topical corticosteroids in the management of HSV stromal keratitis was uncertain; some animal and human studies suggested there was a benefit to treatment whereas others suggested harm. The value of adding an oral antiviral agent to treatment with topical corticosteroids and topical antivirals also was unknown.

The HEDS-I trials were developed to assess the efficacy of topical corticosteroids and oral acyclovir in treating HSV stromal keratitis and iridocyclitis.

HEDS-I consisted of three randomized, placebo-controlled trials. The organizational structure consisted of a data coordinating center and eight clinical centers.

All patients received the topical antiviral trifluridine as prophylaxis against recurrences of HSV epithelial ulceration. Patients were evaluated weekly for 10 weeks, every other week through week 16, and again at 6 months. The primary outcome was the time to development of preset criteria for treatment failure during the 16-week period of examination. Protocol-specific descriptions of the three trials follow.