Infectious keratitis: microbiological review of 297 cases

Abstract

Infectious keratitis is a serious ocular infection that can lead to loss of vision. The aim of the study was to investigate the microbiological characteristics of this infection at the University Hospital of Guadalajara (Spain). We retrospectively reviewed all cases diagnosed between January 2010 and December 2016. During the 7-year study period, 297 corneal scrapes corresponding to 298 patients were performed. Antibiotic treatment previous to the culture occurred in 59 cases (19.5%). Contact lens wear was the most common risk factor (33.2%). Bacterial keratitis accounted for 64.6% of cases, viral keratitis 3.4% and fungal keratitis 1%. A total of 241 bacteria were identified. Gram-positive isolates represented 87.1% and gram-negative 12.7%. Coagulase-negative Staphylococcus were the most common organisms isolated (30.3%). When gram-positive organisms were analyzed, the sensitivity percentages for vancomycin, levofloxacin, gentamicin and tobramicin were: 99.4%, 84.6%, 87.9% and 88.3% respectively. For the gram-negative organisms, the sensitivity percentages for ceftazidime, ciprofloxacin, gentamicin and tobramicin were: 83.3%, 93.5%, 96.3% and 100% respectively. Our study revealed a great predominance of gram-positive organisms. We suggest empirically treating bacterial keratitis from our area with vancomycin and tobramycin, especially severe bacterial keratitis and pretreated cases at the community without clinical response.