Collagenase inhibitors as adjuncts to antibiotic therapy were evaluated in experimentally induced Pseudomonas keratitis in rabbits. Neither the combination of 1% edetic acid (EDTA) and 0.25% polymyxin B sulfate nor that of 1.2% cysteine and 0.25% polymyxin B sulfate was more effective than the polymyxin B sulfate alone. There was a small statistical difference in favor of a combination of edetic acid-cysteine-polymyxin B sulfate when it was compared with an edetic acid-polymyxin B sulfate combination. This difference, although statistically significant, did not appear to be clinically important in the treatment of our experimental model.
Bohigian G, Valenton M, Lejeune C, Okumoto M, Caraway BL. Collagenase Inhibitors in Pseudomonas KeratitisAdjuncts to Antibiotic Therapy in Rabbits. Arch Ophthalmol. 1974;91(1):52-56. doi:10.1001/archopht.1974.03900060056014