Abstract
Purpose: :
To determine the etiology, drug sensitivities, pharmacologic treatment, and short-term visual outcomes of infectious corneal ulcers diagnosed in the Department of Ophthalmology at the University of Mississippi Medical Center, the single tertiary referral center in Mississippi.
Methods: :
We reviewed charts and microbiology reports of patients diagnosed with infectious corneal ulcer between January 2001 and October 2010.
Results: :
We present here the results from 48 patients (eyes) with a confirmed diagnosis of corneal ulcer and available culture results. The sample comprised 50% males and 52% African Americans, with a mean age of 57.3 years. Microorganisms were grown from 29/48 (60.4%) of corneal scrapings; in 5 of these a fungus was grown. Of positive cultures, pure bacterial cultures were obtained from 79.3% (23/29 cases), and pure fungal cultures were obtained from 10.3% (3/29 cases.) Of the bacterial isolates, 6/29 (20.7%) were coagulase negative staphylococcus; 5/29 (17.2%) were Staphylococcus aureus (2 of these 5 were methicillin-resistant); 3/29 (10.3%) were Pseudomonas aeruginosa. In 5 eyes (all with coagulase negative staphylococcus) more than 1 microorganism was grown. Of the bacterial infectious cases, 55.9 % of patients resided in a rural area (Non-Metropolitan Statistical Area), including all of the S. aureus corneal ulcer cases. Of the S. aureus strains, all were sensitive to Vancomycin; of the P. aeruginosa strains, all were sensitive to Tobramycin or a fluoroquinolone. Five of 6 coagulase negative staphylococcus strains and 2/5 S. aureus strains demonstrated resistance to Erythromycin. Of the bacterial infections, 24/29 (82.8%) received a treatment regimen which included fortified Vancomycin or Tobramycin antibiotics. The average visual improvement was -0.37 (logMAR) in the group examined at 2-3 month follow-up.
Conclusions: :
Bacterial organisms are the most common cause of infectious keratitis in this largely rural patient population. Coagulase negative staph was the most common organism identified. The general pattern of drug sensitivities supports the continued use of a fortified Vancomycin or Tobramycin treatment regimen as a first line treatment.
Keywords: keratitis • antibiotics/antifungals/antiparasitics • clinical (human) or epidemiologic studies: prevalence/incidence