Demography, Risk Factors, and Clinical and Microbiological Features of Microbial Keratitis at a Tertiary Eye Hospital in Nepal

BACKGROUND: Infective keratitis is the most common corneal pathology in developing countries. Updated knowledge is needed for its control and proper management. METHODOLOGY: All cases of presumed microbial keratitis that presented in an 18-month period from October 2013 to March 2015 were enrolled. Data collected were demographic profile, risk factors, clinical features, and organisms isolated and their sensitivities. RESULTS: A total of 602 cases of microbial keratitis were enrolled. Mean age of subjects (598 patients) was 47.9 years with 53.8% male. 64.1% worked in agriculture. 38.3% gave history of trauma followed by history of herpetic eye diseases (17.9%) and topical steroid use (14.2%). A total of 473 who were referred came at an average of 21.5 days of symptoms. 14.9% (n=90) of cases were either perforated or impending to perforate at presentation. 69.6% had infiltrate in the visual axis. A total of 516 (85.7%) underwent diagnostic corneal culture. A total of 256 (49.6%) yielded a positive result. Pure bacterial growth was seen in 111 (43.4%), pure fungal growth in 138 (53.9%), and mixed microbial growth was present in 7 (2.7%) cases. Out of 121 bacterial isolates, 95.0% were Gram positive. Streptococcus pneumoniae (45.5%, n=55) was the most common bacterial isolate followed by Staphylococcus aureus (20.6%, n=25). Out of 145 fungal isolates, Aspergillus and Fusarium species were found in equal numbers (n=41, 28.3% each). Over 85% of Gram-positive organisms isolated in the study were sensitive to vancomycin, cefazolin, moxifloxacin, and gatifloxacin. Over 80% of Gram-negative organisms were sensitive to gentamicin, tobramycin, and amikacin. CONCLUSION: Microbial keratitis and associated risk factors occurring in farmers implies a lack of awareness and prevention programs. Delay in reaching tertiary care is resulting in complicated cases. Training of local health workers for prophylaxis, updated guidelines for treating keratitis, and timely referral to higher centers are all important in a chain to decrease the incidence of microbial keratitis.