Clinical characteristics of microbial keratitis in a university hospital in Taiwan

To analyze the clinical and microbiological characteristics of microbial keratitis at the National Taiwan University Hospital in the preceding 10 years.

Retrospective cross-sectional study.

Medical records were reviewed for all patients with clinically diagnosed microbial keratitis presenting at the National Taiwan University Hospital from January 1992 to December 2001. Risk factors, microbial isolations, clinical patterns, treatment, and outcomes were analyzed.

Microbial keratitis was diagnosed for 476 eyes in 453 patients (220 female and 233 male; mean age, 40.7 years). Pseudomonas species were the most commonly isolated organisms (37.7%), followed by fungi (13.5%), staphylococci (8.4%), nontuberculous mycobacteria (7.9%), streptococci (7.6%), and Acanthamoeba (4.4%). Contact-lens wear was the most common predisposing factor (44.3%). Medical treatment was successful for a total of 344 eyes (72.3%), with 132 eyes (27.7%) requiring surgery. The duration from symptom onset to diagnosis of microbial keratitis was statistically significantly shorter for the cases treated medically than the cases treated surgically (7.70 +/- 14.37 and 20.53 +/- 28.85 days, respectively, p =.000000332). Response to medical treatment was more favorable for bacterial infection (except nontuberculous mycobacterial infection) as compared with fungal or Acanthamoeba infection. A total of 84.4% of pseudomonal keratitis cases were cured by medical treatment, while 85% of nontuberculous mycobacterial keratitis cases eventually required surgical treatment to control the infection.

Contact-lens related pseudomonal keratitis was the most common form of microbial keratitis in Taiwan. Early diagnosis and prompt treatment are important for successful management of microbial keratitis.