Microscopic Identification of Etiological Agents of Mycotic Keratitis in Corneal Ulcer Patients at Tertiary Care Eye Hospital, Pondicherry

Abstract

Fungal keratitis is one of the causes of severe ocular morbidity and blindness. The prevalence of fungal keratitis has been increased from 7–63%. Culture is mandatory for an Ophthalmologist to guide treatment. The main objective of this study is to identify the etiological agents of Mycotic keratitis in corneal ulcer patients based on the microscopy. A prospective study was conducted with a total of 200 corneal scrapings were collected during the period of January to Setember 2015. Direct smear examination was followed by culture on blood agar and Sabraoud Dextrose agar and incubated at 37°C for 48 hours (BA) and 25°C for seven days (SDA) 48 hrs . The cultures are stored in sterile distilled water. Fungus was isolated from 79 (39.5%) corneal ulcer patients. Out of which 32 (40.5%) were positive with 10% KOH. In the present study, 85% fungal ulcers were diagnosed in female patients and 15% in male. Among 79 fungus, Aspergillus species, Fusarium species, Curvularia species and unidentified dematiaceous fungi were isolated from corneal ulcers. The bacterial agents were identified in 10 patients (5.0%) by direct gram stain as well as culture. Females are the most prevalent for corneal ulcers. Diagnosis of fungal keratitis patients occurs mostly with Fusarium. It suggests that the most of our corneal ulcer patients are infected with the Fusarium. Another risk factor is contact lens for microbial keratitis at the adult age group in Pondicherry. Majority of the fungal keratitis infections have responded to voriconazole for medical management.

Keywords

• fungal keratitis
• aspergillus
• fusarium
• potassium hydroxide
• slide culture technique