Keratomycosis: An insight into epidemiology, etiology, and antifungal susceptibility testing of causative agents at a tertiary care centre

In India, mycotic keratitis accounts for 7%-63% of infectious keratitis. Ocular trauma being the primary predisposing factor for mycotic keratitis. The present prospective, observational study was conducted on the corneal scrapings from clinically suspected patients of keratomycosis. Samples were processed as per the standard mycological techniques. Antifungal susceptibility testing was performed as per CLSI guidelines M38A2 and M27A3 for mycelial fungi and yeast, respectively. Out of a total of 254 patients suspected to be suffering from mycotic keratitis based on clinical presentation, 68 (26.77%) were positive for fungal aetiology. Male preponderance was observed with male-to-female ratio of 2.78:1. Patients in age group 51-60 years were maximally affected. The majority of the isolates of patients having fungal keratitis were that of Aspergillus sp. (31, 45.6%), followed by Fusarium sp. (12, 17.6%), Curvularia lunata (5, 7.4%), Candida sp. (4, 5.9%), Alternaria sp. (2, 2.9%), Rhodotorula sp. (1, 1.5%), and Acremonium sp. (1, 1.5%). Some rare isolates were Colletotrichum sp. (1), Botryosphaeria dothidea (2), Lasiodiplodia pseudotheobromae (1), and Acrophialophora fusispora (1). Overall, MIC values for natamycin and amphotericin B were high in Aspergillus sp., while Fusarium sp. had high MIC for voriconazole and itraconazole. Candida sp. Curvularia and Alternaria sp. had high MIC values for fluconazole. As mycotic keratitis is an infective condition involving healthy eyes, leading to morbid eye conditions and even blindness, strong clinical suspicion of fungal keratitis followed by timely diagnosis and antifungal susceptibility testing-based treatment may help the clinicians in better management and improvement of the outcome of patients.