Placebo-controlled, double-blind evaluation of the efficacy and safety of yellow mercuric oxide in suppression of eyelid infections.

We tested an over-the-counter ophthalmic ointment, yellow mercuric oxide 1%, for safety and efficacy in decreasing eyelid-margin bacterial-colony counts. Of 150 patients screened for high bacterial levels, 78 were randomized in double-blind fashion to either yellow mercuric oxide bid (41 patients or 53%) or a placebo (37 patients or 47%). Bacterial-colony counts were determined at outset and at days 4 and 7 of treatment. At the conclusion of treatment on day 7, 87% of patients in the mercuric oxide group were successful in decreasing bacterial counts, compared with 59% of patients treated with placebo (P = .01). Side effects were no higher in the active group than in the placebo group. We have shown mercuric oxide 1% to be safe and effective in reducing eyelid bacterial-colony counts in patients with hordeolum and blepharitis.