Comparative Analysis of the Clinical Aspects and Treatment Outcomes of Stenotrophomonas maltophilia Keratitis and Pseudomonas aeruginosa Keratitis

Objectives: We analyzed the clinical aspects and treatment outcomes of Stenotrophomonas maltophilia (SM) keratitis and Pseudomonas aeruginosa (PA) keratitis. Methods: Medical records of 55 inpatients with culture-proven SM (n=21) and PA (n=34) keratitis were retrospectively reviewed. Predisposing factors, clinical characteristics, and treatment outcomes were compared between the SM and PA groups. Results: The mean symptom duration was longer in the SM group than in the PA group (10.4:4.3 days; P=0.012). The most common predisposing factor was corneal trauma (47.6%) in the SM group and contact-lens wear (38.2%) in the PA group. There were no differences in the mean epithelial defect size (12.7:11.9 mm(2); P=0.861), hypopyon (33.3%:44.1%; P=0.428), surgical treatment (4.8%:14.7%; P=0.390), or poor clinical outcomes (26.8%:30.3%; P=0.760) between the SM and PA groups. In multivariate logistic regression, risk factors for poor clinical outcomes were hypopyon (odds ratio [OR], 52.00; P=0.010) in the SM group and symptom duration >= 7 days (OR, 44.32; P=0.015), age >= 60 years (OR, 21.13; P=0.019), and hypopyon (OR, 15.20; P=0.038) in the PA group. Conclusion: Compared with PA keratitis, SM keratitis had slower progression, and its clinical characteristics and treatment results were not worse. In both groups, hypopyon was the risk factor for a poor clinical outcome.