Herpes Stromal Keratitis, Not on Steroid Trial (HEDS-SKN): Patients with active HSV stromal keratitis who had not used a topical corticosteroid in the preceding 10 days were randomized to treatment with topical prednisolone phosphate drops or topical placebo drops. A treatment schedule, starting with 8 drops a day of 1 percent prednisolone phosphate for 7 days, was progressively decreased over 10 weeks in such a way that patients received 1 drop per day of 1/8 percent prednisolone for the last 3 weeks of treatment. Placebo drops were given by the same schedule.