Effect of topical povidone-iodine versus topical ofloxacin on experimental Staphylococcus keratitis.
OBJECTIVE
To compare the antibacterial effect of povidone-iodine (PI) with that of ofloxacin in an experimental model of bacterial keratitis.


METHODS
Staphyloccocal keratitis was induced in 21 eyes of Dutch Belted rabbits by intrastromal inoculation of approximately 280 organisms of Staphylococcus aureus. Six hours later, the animals were divided in four groups treated topically with saline 0.9%, Betadine 10%, Betadine 0.5% or Ofloxacin 0.3% (2 gtt every 30 min for 8 h). The central 8-mm cornea was excised, washed and homogenized. Colony counts were performed on serial 10-fold dilutions plated on blood and brain infusion agar and incubated overnight.


RESULTS
Colony-forming units per cornea were 7.4x10(7) for the saline group compared to 8.2x10(7) for PI 10% (P>0.5), 4.3x10(7) for PI 0.5% (P<0.01) and no organisms for ofloxacin 0.3%.


CONCLUSIONS
Betadine 0.5% demonstrates a statistically significant bactericidal effect compared with untreated staphyloccocal keratitis in our experimental model. Ofloxacin has superior antibacterial effect under the conditions studied. Further improvements in the povidone-iodine formulation are warranted prior to consideration for human keratitis.
Melki
S A
SA
Department of Ophthalmology, Georgetown University Medical Center, Washington, DC, USA. Melki@rcn.com
Safar
A
A
Yaghouti
F
F
Scharper
P
P
Scharper
M
M
Zeligs
B
B
MacDowell
A L
AL
Goldberg
M A
MA
Lustbader
J
J
D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D003315:Cornea / Q000382:microbiology; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D007466:Iodophors / Q000008:administration & dosage*; D007634:Keratitis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D008297:Male; D015242:Ofloxacin / Q000008:administration & dosage*; D009883:Ophthalmic Solutions; D011206:Povidone-Iodine / Q000008:administration & dosage*; D011817:Rabbits; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification
D000890:Anti-Infective Agents; D007466:Iodophors; D009883:Ophthalmic Solutions; D011206:Povidone-Iodine; D015242:Ofloxacin