Risk factors and clinical outcomes between fungal and bacterial keratitis: a comparative study.
OBJECTIVE
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.
Wong
T Y
TY
Singapore National Eye Center, Singapore.
Ng
T P
TP
Fong
K S
KS
Tan
D T
DT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001419:Bacteria / Q000302:isolation & purification; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects / Q000382:microbiology; D003315:Cornea / Q000382:microbiology* / Q000601:surgery; D065306:Corneal Injuries; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000209:etiology*; D015821:Eye Infections, Fungal / Q000188:drug therapy / Q000209:etiology* / Q000601:surgery; D005131:Eye Injuries / Q000150:complications; D005260:Female; D005658:Fungi / Q000302:isolation & purification; D006801:Humans; D007634:Keratitis / Q000209:etiology / Q000382:microbiology* / Q000628:therapy; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012422:Rupture, Spontaneous
D000900:Anti-Bacterial Agents