Original Article Singapore Med J 2008; 49 (1) : 67 Microbial keratitis: aetiological diagnosis and clinical features in patients admitted to Hospital Universiti Sains Malaysia Norina T J, Raihan S, Bakiah S, Ezanee M, Liza-Sharmini A T, Wan Hazzabah W H ABSTRACT Intr oduction: 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. R esults: 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. Keywords: blindness, corneal ulceration, eye infections, infectious corner ulcer, microbial keratitis, Pseudomonas aeruginosa Singapore Med J 2008; 49(1): 67-71 INTRODUCTION Microbial keratitis is a major cause of monocular blindness in developing countries. This represents only a small fraction of millions who suffer visual loss as a result of corneal trauma and subsequent microbial keratitis in the world. (1) Corneal scarring listed second only to cataracts as an important cause of blindness and visual impairment in many developing countries in Asia, Africa and the Middle East. (1) Based on the National Eye Survey conducted in Malaysia in 1996, (2) infectious corneal ulcer was found to be the fourth most common cause of blindness in Malaysia. Since the discovery of antibiotics and the advancement of medical technology, the incidence of microbial keratitis has been drastically reduced in developed countries. The incidence of microbial keratitis is still quite high in developing countries, mainly due to lack of medical awareness, or, in certain parts, due to inaccessibility to medical treatment. In 1996, Gonzales et al reported on the incidence of corneal ulceration in the Madurai District, South India, yielding an annual incidence of 11.3 per 10,000 population. (3) The incidence of corneal ulceration in the Olmstead County, Minnesota, in eight years of study from 1980 to 1988, was 11.0 per 100,000 population, this is almost ten times less than in South India. (4) Malaysia, a developing country in the race to become a developed country by year 2020, Department of Ophthalmology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, Kota Bharu 16150, Kelantan, Malaysia Norina TJ, MD Registrar Raihan S, MD Registrar Bakiah S, MD, MMed Medical Lecturer and Ophthalmologist Ezanee M, MBBS, MMed Ophthalmologist Liza-Sharmini AT, MBBS, MMed Senior Lecturer and Ophthalmologist Wan Hazzabah WH, MD, MMed Senior Lecturer Correspondence to: Dr Tengku-Norina Tuan Jaffar Tel: (60) 9 766 4585 Fax: (60) 9 765 3370 Email: tengkunorina @yahoo.com