Prevalence of Fungal Keratitis in Suspected Keratomycosis Cases Over Five Years in Southeastern Iran

Abstract

Background: Keratomycosis is a fungal corneal infection that can be vision-threatening and even cause eye discharge. Objectives: This study aimed to investigate and diagnose fungal keratitis in patients suspected of having corneal lesions. Methods: This descriptive cross-sectional study was conducted from fall 2018 to fall 2023 in 94 patients with suspected fungal keratitis at the ophthalmology clinics of Al-Zahra Hospital in Sistan and Baluchestan province. First, corneal scraping samples were prepared from the patients, then direct testing and culture were performed in standard mycological media. Fungal agents were identified based on microscopic and macroscopic features of the colonies. Results: The results of the tests showed that 37 samples (39.36%) out of 94 samples were positive by direct potassium hydroxide (KOH) test and Gram stain, and 32 samples (34.04%) were positive only by culture test. Twenty-five samples (26.60%) were positive simultaneously in both direct KOH-Gram stain and culture tests. The frequency of fungal species was Fusarium spp. (92.6%), Aspergillus species (5.3%), Penicillium species, and yeasts 1.1%, and 1.1%, respectively. Conclusions: Fungal keratitis can be caused by a variety of fungi if the necessary conditions are provided, such as corneal injury from plant stems and leaves. The negative direct test in the majority of patients emphasizes the importance and necessity of performing a culture of the sample to diagnose keratomycosis.