Bacterial corneal ulcer: a multivariate study.

A retrospective clinicomicrobiological review of 314 patients with bacterial corneal ulcers from January 1982 to December 1992 was performed. Multivariate statistical analysis was done with multiple logistic regression using PROC LOGIST of SAS statistical software. Positive cultures were grown from 134 (42.7%) of the patients. Pseudomonas aeruginosa, staphylococci, and Acinetobacter spp. were the most frequent pathogens. Significant associations between contact lens use and P. aeruginosa (odds ratio, OR 8.16), between previous herpes simplex keratitis and Streptococcus spp. (OR 18.2) were found. Acinetobacter spp. occurred more frequently in eyes with burn and/or lagophthalmos (OR 13.1/26.2). Staphylococcus aureus was associated with trauma (OR 6.27) and age under 50 (OR 5.08-13.6). Nonpseudomonal gram-negative bacilli were associated with age over 50 (OR 3.24). Drug sensitivity tests for these isolated microorganisms showed that vancomycin and ceftazidime were the most effective agents.