Microbial keratitis: aetiological diagnosis and clinical features in patients admitted to Hospital Universiti Sains Malaysia

INTRODUCTION: Corneal ulceration remains one of the major causes of blindness in developing countries, including Malaysia. Our objective is to determine the epidemiological characteristics, clinical features, risk factors and the aetiology of microbial keratitis in patients admitted to Hospital Universiti Sains Malaysia (HUSM). METHODS: All patients with microbial keratitis admitted to our hospital over a 16-month period from January 2004 to April 2005 were included in the study. Sociodemographic data and information pertaining to risk factors were recorded. All patients underwent examination with slit lamp biomicroscopy and corneal scrapings were sent for microbiological diagnosis. RESULTS: 42 patients were included in the study; 26 were male and 16 were female, with mean age of 44.5 (+/- 20.9) years. History of previous corneal trauma was present in 26 (61.9 percent) patients. Central location ulcers were more predominant (69 percent) than peripheral ulcers. Cultures from corneal scrapings were positive in 29 cases (69 percent). Of those individuals with positive cultures, 23 (79.3 percent) had pure bacterial infection, four (13.8 percent) had pure fungal infection and two (6.9 percent) had mixed growth. The most common bacterial pathogen isolated was Pseudomonas aeruginosa (40.5 percent), followed by Streptococcus pneumoniae (7.5 percent). Fungal pathogens which were isolated include Fusarium spp. (4.7 percent) and Aspergillus spp. (2.4 percent). CONCLUSION: Central corneal ulceration is a problem among patients presenting with microbial keratitis in HUSM. It often occurs after corneal trauma. These findings have important public health implications for the treatment and prevention of visual morbidity due to an infective cause.