Effect of topical dexamethasone and ciprofloxacin on bacterial flora of healthy conjunctiva

Eye (Lond). 2004 Mar;18(3):249-52. doi: 10.1038/sj.eye.6700631.


Purpose: To investigate the effects of topical dexamethasone and ciprofloxacin, alone and in combination, on the colony counts of conjunctival bacterial flora of healthy subjects.

Methods: A total of 100 healthy subjects were randomly divided into four groups, consisting of 25 subjects each. Group 1 was treated with dexamethasone phosphate 0.1% (Maxidex). Group 2 was treated with ciprofloxacin 0.3% (Ciloxan) and Group 3 with a combination of these drugs. Group 4 received artificial tear solution (Tears Naturale) and served as control. The drops were administered one drop every 1 min. A pretreatment culture and recultures at 30, 90, and 180 min after application of final drops were performed on all subjects. The bacterial growth was evaluated in a quantitative manner. All cultures were performed in a double-masked fashion. ANOVA test was used for statistical analyses.

Results: While there was no significant difference among mean number of pretreatment colonies between the groups (P=0.85); the differences at 30, 90, and 180 min were statistically significant (P<0.001). During the study there was no statistically significant change in colony counts in Groups 1 and 4 (P=0.66 and 0.55, respectively). The colony count numbers decreased significantly at 30 and 90 min in Group 2 (P<0.001 and P=0.004) and at 30 min in Group 3 (P=0.002).

Conclusion: Topically applied dexamethasone did not cause a significant change in colony counts of the healthy conjunctiva. Both ciprofloxacin and a combination of ciprofloxacin and dexamethasone were effective in the reduction of bacterial ocular flora.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Administration, Topical
  • Adult
  • Aged
  • Analysis of Variance
  • Anti-Infective Agents / administration & dosage*
  • Anti-Inflammatory Agents / administration & dosage*
  • Ciprofloxacin / administration & dosage*
  • Colony Count, Microbial / methods
  • Conjunctiva / drug effects
  • Conjunctiva / microbiology*
  • Dexamethasone / administration & dosage*
  • Drug Therapy, Combination
  • Female
  • Glucocorticoids / administration & dosage*
  • Humans
  • Male
  • Middle Aged


  • Anti-Infective Agents
  • Anti-Inflammatory Agents
  • Glucocorticoids
  • Ciprofloxacin
  • Dexamethasone