Clinical and microbiological profile of infectious keratitis in an area of Madrid, Spain.

INTRODUCTION

To study antibiotic susceptibility in bacterial keratitis (BK), its profile over 10 years and its influence on ophthalmological practice.

METHODS

Retrospective review of BK with positive corneal scraping over a 10-year period. Risk factors for keratitis, visual acuity (VA), empirical topical treatment, corneal infection characteristics and outcomes were analyzed for BK due to Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa and Propionibacterium acnes.

RESULTS

389 positive corneal scrapings were collected. All Gram-positive bacteria were susceptible to vancomycin. P. aeruginosa demonstrated >90% sensitivity to the most-commonly-used topical antibiotics. Susceptibility to methicillin was 90.2% for S. aureus and 66.3% for S. epidermidis. The results of 215 patients were available. 1.9% required enucleation and 2.8% required surgical treatments. Final VA improved after treatment in keratitis due to S. aureus (p=0.026) and S. epidermidis (p=0.005). There was a correlation between S. aureus resistance to methicillin (p=0.002) and levofloxacin (p=0.043) and enucleation (20% and 10%, respectively) compared with a 0% rate of enucleation in S. aureus-susceptible keratitis.

CONCLUSIONS

BK due to S. pneumoniae is very aggressive irrespective of antibiotic sensitivity. S. aureus was frequently isolated in patients with systemic diseases. It causes severe keratitis and remains moderately resistant to methicillin and levofloxacin. For this reason, keeping vancomycin in empirical regimens is believed to be necessary.