Does in vitro susceptibility predict clinical outcome in bacterial keratitis?

Am J Ophthalmol. 2008 Mar;145(3):409-412. doi: 10.1016/j.ajo.2007.11.004. Epub 2008 Jan 22.


Purpose: To determine whether clinical outcomes in bacterial keratitis are associated with antibiotic susceptibility.

Design: Retrospective, ancillary study using data and samples from a completed randomized clinical trial.

Methods: Forty-two patients were enrolled with culture-confirmed bacterial keratitis at Aravind Eye Hospital in South India. All patients received topical moxifloxacin and were randomized to receive either topical prednisolone phosphate or placebo. Outcomes included time to epithelialization, best spectacle-corrected visual acuity (BSCVA), and infiltrate/scar size at three months. Bacterial isolates were cultured, and minimum inhibitory concentration (MIC) to moxifloxacin was measured using Etests. Multiple linear regression was used to assess the effect of MIC on outcome, adjusting for enrollment characteristics.

Results: MIC was associated with three-month infiltrate/scar size: each two-fold increase in MIC was associated with a 0.33-mm average diameter increase in scar size (P=.01). MIC was not associated with three-month BSCVA (P=.71) or time to epithelialization (P=.35).

Conclusions: MIC was associated with infiltrate/scar size in bacterial keratitis. An ongoing larger, multicenter trial should provide further information on whether this association is maintained across subgroups of organisms.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / pharmacology*
  • Anti-Infective Agents / therapeutic use
  • Aza Compounds / pharmacology*
  • Aza Compounds / therapeutic use
  • Bacteria / drug effects*
  • Corneal Ulcer / diagnosis
  • Corneal Ulcer / drug therapy
  • Corneal Ulcer / microbiology*
  • Disease Susceptibility
  • Eye Infections, Bacterial / diagnosis
  • Eye Infections, Bacterial / drug therapy
  • Eye Infections, Bacterial / microbiology*
  • Fluoroquinolones
  • Humans
  • Microbial Sensitivity Tests
  • Moxifloxacin
  • Pilot Projects
  • Prednisolone / therapeutic use
  • Quinolines / pharmacology*
  • Quinolines / therapeutic use
  • Randomized Controlled Trials as Topic
  • Retrospective Studies
  • Treatment Outcome
  • Visual Acuity


  • Anti-Infective Agents
  • Aza Compounds
  • Fluoroquinolones
  • Quinolines
  • Prednisolone
  • Moxifloxacin