Incidence and risk factors of bacteria causing infectious keratitis

Objectives: To study the incidence and risk factors of the bacteria causing infectious keratitis among patients in Qassim province of Saudi Arabia. Methods: This is a cross sectional study conducted at the Department of Optometry, College of Applied Medical Sciences, Qassim University, Qassim, Kingdom of Saudi Arabia from December 2010 to May 2011. One hundred patients suspected of keratitis were subjected to clinical examinations. A total of 115 corneal swabs from these cases were collected under aseptic conditions for bacteriological examinations. Results: Culture of the corneal swabs revealed Pseudomonas aeruginosa (25.2%), Staphylococcus aureus ( 15.7%), and unclassified bacteria (13.9%). However, 52 swabs of infectious keratitis cases (45.2%) were negative to bacteria. Contact lens wearing (44.4%) was the most common risk factor among the examined patients, followed by corneal trauma (21.7%), ocular surface disease (11.3%), and corneal surgery (7%). No significant correlation was observed between systemic risk factor and clinical presentation. Conclusion: It could be concluded that infectious keratitis was mostly due to Pseudomonas aeruginosa and Staphylococcus aureus . Therefore, strict measures are recommended to control and treat infectious keratitis to avoid visual complications.