Clinical evaluation of trimethoprim-containing ophthalmic solutions in humans.

We studied trimethoprim in combination with sulfacetamide and polymyxin B and also in combination with polymyxin B alone (without the sulfacetamide) to determine the efficacy and safety of these new antibiotic combinations in the eyes of patients with bacterial conjunctivitis or blepharitis. Patients were selected for the study if they showed at least three of the following criteria: (1) symptoms of a surface ocular infection; (2) a purulent discharge; (3) a polymorphonuclear neutrophilic response on Giemsa stain; (4) a history of recent exposure to an infected individual; (5) a history of an inadequately treated surface bacterial infection. Trimethoprim-sulfacetamide-polymyxin B and polymyxin B-neomycin-gramicidin (Neosporin, the control) eliminated bacteria from the eyes of patients with conjunctivitis or blepharitis with equal effectiveness. There was no loss of effectiveness when trimethoprim-polymyxin B was compared with trimethoprim-sulfacetamide-polymyxin B, suggesting that the sulfacetamide was not a necessary component. The combination antibiotic containing trimethoprim and polymyxin B appears to be an effective topical antibiotic solution for the treatment of ocular surface infections.