Clinical and microbiologial profile of bacterial and fungal keratitis: A comparison of patients with and without diabetes mellitus

Abstract

The aim of the study was to evaluate the predisposing factors, clinical features, causative microorganism, and response to treatment, among persons of infective keratitis, with and without diabetes mellitus and to determine differences between the two groups. This prospective study enrolled 26 patients of infective keratitis who had diabetes mellitus and 52 patients without diabetes mellitus, by consecutive sampling who attended the ophthalmology department at a tertiary care institute. Detailed clinical evaluation and microbiological evaluation were done. Treatment was initiated according to clinical diagnosis. The patients were followed up at 2 weeks, 1 month, and 3 months. Statistical testing was done using Chi-square test and Fisher’s exact test for qualitative variables. Quantitative variables were expressed as means and standard deviations. The variables between the two groups were compared using Student’s t-test and Wilcoxon test, where appropriate. Shapiro–Wilk test was used to test normality of data. Analysis was done using the SPSS software. Urban population, monsoon season, and outdoor work were associated more commonly with microbial keratitis. Ocular trauma (69.2%) was the most common risk factor. A greater proportion of patients with diabetes (46.2%) did not have a history of ocular injury compared to those without (23.8%). Poor glycemic control increased severity of keratitis (P = 0.023). Redness and pain were the most common symptoms in both groups. Corneal sensations were significantly reduced in patients with diabetes mellitus. Diabetes mellitus was significantly associated with central ulcers (46.2%), hypopyon (50%) in anterior chamber, and fungal keratitis (35%). Hypopyon and depth of ulcer were significant predictors (P = 0.018 and 0.006) of the time taken for the infective keratitis to heal. Pseudomonas aeruginosa (19.2%) was the most common bacteria isolated in diabetic patients and Methicillin-sensitive Staphylococus aureus (10.3%) among nondiabetic patients. Fusarium was the most common fungus isolated among both groups. Ulcers healing with leukomatous opacities were higher, and the frequency of perforated corneal ulcers was also higher among diabetic patients (P = 0.026). Posttreatment visual acuity showed a statistically significant improvement only in patients without diabetes mellitus. Significant differences existed between the two groups regarding clinical and microbiologial profile. Aggressive treatment, strict glycemic control, and high index of suspicion for fungal keratitis are important in managing microbial keratitis patients with diabetes mellitus.