Purpose
To compare the laboratory results of central corneal ulcers in contact lens and non-contact lens wearers seen at the University of Chicago between 2002 and 2009 to determine the relative frequencies of pathogens causing bacterial ulcers and their susceptibility to antibiotic treatment.
Methods
A retrospective chart review was done for patients identified as having a bacterial central corneal ulcer between the years 2002 and 2009. The culture results of the central ulcers and the bacterial susceptibility to different antibiotics were analyzed for each subset.
Results
314 charts were identified by ICD-9 coding of “ulcer” and reviewed. A total of 128 central bacterial ulcers were identified, 52 in non-contact lens wearers and 76 in contact lens wearers. 111 (86.7%) of these ulcers were cultured and 65 (58.5%) had positive cultures. The most common organism isolated in non-contact lens wearers was coagulase negative Staphylococci (n=10) whereas the most common organism in contact lens wearers was Pseudomonas aeruginosa (n=22). Some of the organisms common to both subsets include Pseudomonas aeruginosa, coagulase negative Staphylococci, alpha hemolytic Streptococci, Staphylococcus aureus, Serratia, Corynebacterium, MRSA, and Escherichia coli. The organisms that exclusively grew in contact lens wearers include Klebsiella (n=2), Achromobacter (n=2), non-alpha hemolytic Streptococcus (n=1), Actinobacter (n=1) and Micrococcus (n=1). The organisms isolated in non-contact lens wearers only include Moraxella (n=5), MSSA (n=3), gram negative bacilli (n=2), Streptococcus pneumoniae (n=1) and gram positive bacillus (n=1). Of antibiotics available in a topical ophthalmic formulation, only vancomycin demonstrated no resistance among bacteria tested in non- contact lens wearers. Gentamicin, levofloxacin, tobramycin, trimethoprim-sulfamethoxazole and vancomycin demonstrated no resistance among bacteria tested in contact lens wearers.
Conclusions
Our study showed that the most common organism in non-contact lens associated central ulcers was coagulase negative Staph which was consistently susceptible to vancomycin, and Pseudomonas in contact lens wearers which was susceptible to ciprofloxacin, gentamicin, levofloxacin, and tobramycin. With this information, empiric treatment of corneal ulcers can be more specific.
Keywords: 573 keratitis •
433 bacterial disease •
422 antibiotics/antifungals/antiparasitics