SUSCEPTIBILITY OF CORNEAL AND CONJUNCTIVAL PATHOGENS TO CIPROFLOXACIN

Ciprofloxacin 0.3% ophthalmic solution has been shown to be effective in the treatment of bacterial keratitis and conjunctivitis, and many p hysicians use ciprofloxacin as sole therapy in these conditions. In th is retrospective study, we found seven of 84 isolates from corneal and conjunctival cultures that were resistant to ciprofloxacin. All of th e resistant organisms were gram positive. Six of the isolates (Staphyl ococcus aureus, Staphylococcus hominis, and four isolates of the Strep tococcus viridans group) were from corneal cultures, and one (Staphylo coccus aureus) was from a conjunctival culture. Yearly records of syst emic isolates from 1988 to 1993 (n = 35,308) demonstrated a statistica lly significant decrease in susceptibility for several organisms that are common pathogens in the conjunctiva and cornea: Pseudomonas aerugi nosa (95-90%, p = 0.001); Staphylococcus aureus (96-87%, p < 0.0001); Staphylococcus spp,, coagulase negative (97-81%, p < 0.0001): Enteroco ccus spp. (92-79%, p < 0.0001); Acinetobacter anitratus (97-77%, p = 0 .0006); and Enterobacter cloacae (100-96%, p = 0.03). Although the sus ceptibility of corneal and conjunctival isolates in this series remain ed relatively high (91.7%), a much larger series of systemic isolates that are common ocular pathogens revealed a statistically significant increase in resistance to ciprofloxacin over the preceding 5 years.