Bacterial keratitis in and around Visakhapatnam.

ABSTRACT

Introduction: Microbial keratitis is a common potentially vision threatening ocular infection caused by bacteria, fungi, viruses or parasites. Bacterial corneal ulceration is an ocular emergency. Hence an understanding of epidemiological features is important in rapid recognition, timely institution of therapy and optimal management. Objectives: To isolate the specific bacterial pathogens and to determine their antibiotic susceptibility pattern. To determine the risk factors and other epidemiological characteristics of infectious keratitis, and the importance of direct microscopy. Methods: Corneal scrapings were collected under strict aseptic conditions from each patient. The scrapings were subjected to direct microscopy (Gram’s stain), culture, and identification by standard microbiological techniques, and antibiotic sensitivity testing was performed by Kirby-Bauer disc diffusion technique. Results & Conclusions: Bacterial isolates were obtained from 41 out of 100 samples. Gram positive isolates accounted for 56.09% of the isolates, and Gram negative isolates 43.90%. Pseudomonas aeruginosa was the predominant bacterial isolate (26.82%), followed by Streptococcus pneumoniae (19.51%). Corneal ulcers showed a higher prevalence in the 21-50yr age group (58.53%), with agricultural labourers contributing to 51.21%. Peak incidence of corneal ulceration was seen during the monsoon season (June – September). History of trauma to the eye, with vegetative matter, was the most frequent predisposing factor noted, representing to 65.85% of the cases. Both Gram negative and Gram positive isolates were more commonly sensitive to amikacin and gentamicin. Both smear & culture positivity was noted in 35 out of 41 samples by Gram’s stain giving a sensitivity of 85.36%.