Risk factors and clinical outcomes between fungal and bacterial keratitis: a comparative study

CLAO J. 1997 Oct;23(4):275-81.


Purpose: Previous studies on fungal and bacterial keratitis were descriptive single case series analysis. We conducted a hospital-based retrospective study to evaluate fungal and bacterial keratitis using a case-control design to compare risk factors and clinical outcomes.

Methods: Twenty-nine cases of culture-positive fungal keratitis seen over a 5-year period were compared to 51 cases of culture-positive bacterial keratitis seen over a 21 months period. Using bacterial keratitis as the reference group, case-control odds ratios (OR) for predisposing factors and cohort relative risks (RR) for clinical outcomes associated with fungal keratitis were derived. Mantel-Haenszel adjustment procedures were used to examine the respective roles of confounding and intermediate variables.

Results: Compared to bacterial keratitis, fungal keratitis was significantly more likely to be associated with ocular trauma (OR = 2.69, 95% confidence interval [CI], 1.06-6.86) but significantly less likely to be associated with contact lens wear (OR = 0.16, 95% CI, 0.04-0.67) and preexisting ocular diseases (OR = 0.23, 95% CI, 0.07-0.72). Fungal keratitis was more likely to perforate than bacterial keratitis (RR = 5.28, 95% CI, 1.35-20.66) and to require penetrating keratoplasty (OR = 5.86, 95% CI, 2.06-16.69).

Conclusions: Fungal keratitis appears more likely to result from ocular trauma, whereas bacterial keratitis is more likely to result from contact lens wear and pre-existing ocular diseases. Fungal keratitis is more likely than bacterial keratitis to result in perforation and require penetrating keratoplasty.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Bacterial Agents / therapeutic use
  • Bacteria / isolation & purification
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Contact Lenses, Hydrophilic / adverse effects
  • Contact Lenses, Hydrophilic / microbiology
  • Cornea / microbiology*
  • Cornea / surgery
  • Corneal Injuries
  • Eye Infections, Bacterial / drug therapy
  • Eye Infections, Bacterial / etiology*
  • Eye Infections, Fungal / drug therapy
  • Eye Infections, Fungal / etiology*
  • Eye Infections, Fungal / surgery
  • Eye Injuries / complications
  • Female
  • Fungi / isolation & purification
  • Humans
  • Keratitis / etiology
  • Keratitis / microbiology*
  • Keratitis / therapy
  • Keratoplasty, Penetrating
  • Male
  • Middle Aged
  • Retrospective Studies
  • Risk Factors
  • Rupture, Spontaneous


  • Anti-Bacterial Agents