Infectious crystalline keratopathy caused by gram-negative bacteria

PURPOSE: To identify the characteristics and outcomes of infectious crystalline keratopathy caused by gram-negative bacteria. METHODS: We reviewed 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 gram-negative rods and those with keratitis caused by gram-positive cocci. RESULTS: Eighteen patients (mean age +/- SD, 59 +/- 17 years) displayed unilateral culture-positive infectious crystalline keratopathy, Among 18 eyes with crystalline keratopathy, five occurrences (28%) were caused by gram negative rods (Acinetobacter lwoffi, Citrobacter koseri, Enterobacter aerogenes, Pseudomonas aeruginosa, and Stenotrophomonas 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 factors, clinical appearance, or visual outcome was found between infections caused by gram-negative bacteria and those caused by gram-positive bacteria. CONCLUSIONS: Gram-negative bacteria can cause infectious crystalline keratopathy but have distinguishing features from infectious crystalfine keratopathy caused by streptococci and other gram-positive bacteria. Appropriate laboratory evaluation is therefore necessary to guide specific antimicrobial therapy.