Influence of fluoroquinolone susceptibility on the therapeutic response of fluoroquinolone-treated bacterial keratitis

Arch Ophthalmol. 2003 Sep;121(9):1229-33. doi: 10.1001/archopht.121.9.1229.


Objective: To estimate how a corneal isolate's minimal inhibitory concentration for a fluoroquinolone agent affects the rate of clinical response of bacterial keratitis to fluoroquinolone therapy.

Design: Prospective cohort study.

Methods: Six hundred sixty-three individuals with suspected bacterial keratitis underwent diagnostic corneal scraping and were treated with topical 0.3% ciprofloxacin solution or ointment. Of 407 patients with culture-confirmed bacterial keratitis, improvement and cure rates with ciprofloxacin monotherapy were estimated for 391 who had in vitro ciprofloxacin susceptibility of the principal corneal isolate.

Main outcome measures: Slitlamp biomicroscopic assessment for clinical improvement of corneal inflammation and for clinical cure with complete reepithelialization.

Results: Adjusted rates of improvement and of cure were reduced, respectively, by 43% (95% confidence limits, 8%, 64%) and by 29% (95% confidence limits, 0%, 49%) among corneal infections having a ciprofloxacin minimal inhibitory concentration above 1.0 micro g/mL compared with those with more sensitive isolates.

Conclusions: Corneal infection by relatively ciprofloxacin-resistant bacteria responds more slowly to ciprofloxacin therapy. Antibacterial susceptibility testing of corneal cultures may predict the fluoroquinolone therapeutic response rate of bacterial keratitis.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anti-Infective Agents / pharmacology
  • Anti-Infective Agents / therapeutic use*
  • Bacteria / drug effects*
  • Bacteria / isolation & purification
  • Ciprofloxacin / pharmacology
  • Ciprofloxacin / therapeutic use*
  • Cornea / microbiology
  • Corneal Ulcer / drug therapy*
  • Corneal Ulcer / microbiology
  • Drug Resistance, Bacterial
  • Eye Infections, Bacterial / drug therapy*
  • Eye Infections, Bacterial / microbiology
  • Female
  • Humans
  • Male
  • Microbial Sensitivity Tests*
  • Middle Aged
  • Ointments
  • Ophthalmic Solutions
  • Prospective Studies


  • Anti-Infective Agents
  • Ointments
  • Ophthalmic Solutions
  • Ciprofloxacin