POVIDONE-IODINE (BETADINE) IN THE TREATMENT OF EXPERIMENTAL PSEUDOMONAS-AERUGINOSA KERATITIS

Topical 5% povidone-iodine for the treatment of corneal ulcers was obs erved in Sierra Leone, West Africa by one of us (D.J.D.). To test the efficacy of topical 5% povidone-iodine for infectious keratitis, exper imental Pseudomonas aeruginosa keratitis was induced in 12 rabbits by first abrading the central 3 mm of corneal epithelium. Thirty millilit ers of broth of P. aeruginosa strain ATCC 27835 (1.8 x 10(7) viable ba cteria) was dropped twice on the wounded cornea. After 22 h, all corne as were clinically infected. Eight rabbits were treated with 5% povido ne-iodine solution and four with 0.9% NaCl solution. All were given ho urly drops. Twenty-four hours after treatment began, the central 8-mm button of the infected cornea was excised, homogenized, and serial dil utions plated onto MacConkey agar. The total number of viable Pseudomo nas organisms was calculated. The treatment group had 5.2+/-0.4 CFUs ( colony-forming units) per cornea. The control group had 4.8+/-0.4 CFUs per cornea (p = 0.11). The clinical scores (Hobden grading system) we re 6.9+/-1.5 for the treated group and 7.3+/-2.5 for the control group (p = 0.74). There was no statistical difference between the treated a nd control groups. Povidone-iodine (5%) is not effective in the acute treatment of P. aeruginosa keratitis in this rabbit model.