Mycotic keratitis in India: a five-year retrospective study

Background: Mycotic keratitis is a fungal infection of the cornea. This infection is difficult to treat and it can lead to severe visual impairment or blindness. It is worldwide in distribution, but is more common in the tropics and subtropical regions. Trauma is the major predisposing factor, followed by ocular and systemic defects, prior application of corticosteroids, and prolonged use of antibiotic eye-drops. The objective of this study was to determine causative agents and to identify the predisposing factors of mycotic keratitis. Methodology: Corneal scrapings from 90 corneal ulcer patients with suspected fungal etiology were subjected to direct examination by 10% KOH mount, Gram stain and culture. Results: This study included 90 subjects with corneal ulcers, based on clinical suspicion, of whom 41 cases were diagnosed with mycotic keratitis in the laboratory. Among these 41 cases, culture showed fungal growth only in 36 cases whereas the remaining five cases were positive only by potassium hydroxide (KOH) preparation. Males were more commonly affected and were mostly in the age group of 31-40 years. Aspergillus flavus was the most common fungus isolated followed by fusarium solani. Conclusion: Rapid diagnosis and early institution of antifungal therapy is necessary to prevent ocular morbidity and blindness. Although culture helps in definite diagnosis and identification, direct microscopic detection of fungal structures in corneal scrapes or biopsies permits a rapid presumptive diagnosis.