INFECTIOUS CRYSTALLINE KERATOPATHY CAUSED BY GRAM-NEGATIVE BACTERIA

PURPOSE: To identify the characteristics and outcomes of infectious cr ystalline keratopathy caused by gram-negative bacteria. METHODS: We re viewed all patients treated at a university eye center for infectious crystalline keratopathy from 1978 through 1995 and performed a nested case-comparison study by comparing patients with keratitis caused by g ram-negative rods and those with keratitis caused by gram-positive coc ci. RESULTS: Eighteen patients (mean age +/- SD, 59 +/- 17 years) disp layed unilateral culture-positive infectious crystalline keratopathy, Among 18 eyes with crystalline keratopathy, five occurrences (28%) wer e caused by gram negative rods (Acinetobacter lwoffi, Citrobacter kose ri, Enterobacter aerogenes, Pseudomonas aeruginosa, and Stenotrophomon as maltophilia), 10 (55%) were caused primarily by gram-positive cocci , and three (17%) were caused primarily by yeasts, Four cases grew two different isolates. No. significant difference in predisposing factor s, clinical appearance, or visual outcome was found between infections caused by gram-negative bacteria and those caused by gram-positive ba cteria. CONCLUSIONS: Gram-negative bacteria can cause infectious cryst alline keratopathy but have distinguishing features from infectious cr ystalfine keratopathy caused by streptococci and other gram-positive b acteria. Appropriate laboratory evaluation is therefore necessary to g uide specific antimicrobial therapy.