Corneal ulcer: A prospective clinical and microbiological study

Abstract

Background: It is important to study the epidemiologic features and predisposing factors of corneal ulcer and subsequently to find out its causative agents and their antimicrobial susceptibility patterns in a given community, climate and culture. Aims & Objectives: This prospective study of 100 cases of corneal ulcer was undertaken to bring out the bacterial and fungal prevalence among different age groups. Materials and Methods: Corneal scrapings were collected from all patients. One corneal swab and three corneal scrapings were collected. Direct examination of samples was done by potassium hydroxide wet mount and gram stained smear and then inoculated onto blood agar, MacConkey’s agar and Saboraud's dextrose agar media. Identification of fungal growth finally was done based on its macroscopic and microscopic features. Bacterial colonies were identified by Gram staining and standard biochemical tests and antimicrobial susceptibility testing was carried out for each bacterial isolate. Results: Out of total 100 specimens of corneal ulcer, only 55% cases were found to be culture positive in which bacteria were more frequently isolated than fungi. Staphylococcus aureus and Aspergillus spp were the most frequent bacterium and fungus. The incidence was higher in males and in age group of >40-60 years. While S. aureus was found to be most sensitive to vancomycin, Staphylococcus epidermis was most sensitive to cefazoline. Conclusion: S. aureus and Aspergillus spp were the most common isolate to be associated with corneal ulcer, and the incidence was higher in rural population, especially farmers, who were constantly exposed to vegetative matter.