Clinical Manifestations and Prognostic Factors of Fungal Keratitis: Analysis in Patients Over a 20-year Period

Abstract

Purpose: To describe the clinical manifestations, causative organisms, treatment, and prognostic factors of fungal keratitis based on analysis of patients over the past 20 years. Methods: A total of 177 patients (177 eyes) with fungal keratitis, who were diagnosed by smears and cultures, were reviewed retrospectively. Sex, age, predisposing factors, causative organisms, clinical manifestations, treatment, and prognosis were evaluated. The patients were divided into three groups: only potassium hydroxide (KOH)-positive, only culture-positive, and KOH- and culture-positive. Logistic regression was performed to identify the factors associated with a poor clinical outcome. Results: The mean age of the patients was 67.4 ± 11.3 years; 107 (60.5%) patients were men. The most common predisposing factor was ocular trauma (57.6%), especially by plants (29.4%). The most prevalent filamentous fungi were Fusarium species (31.6%, 49 isolates), and the most prevalent yeasts were Candida species (11.0%, 17 isolates). In cases of bacterial and fungal keratitis, filamentous fungus with Gram-positive bacterial infection (70.7%, 29/41) was the most common presentation. Visual improvement after treatment was common in the KOH-positive group (79.2%, 19/24), while visual deterioration after treatment was common in the culture-positive group (40.4%, 36/89). Previous ocular disease (odds ratio [OR]: 3.744, p = 0.010), hypopyon (OR: 2.941, p = 0.030), and surgical treatment (OR: 24.482, p < 0.001) were risk factors for a poor clinical outcome in the multivariate logistic regression model. Conclusions: Clinical prognosis was good in the KOH-positive only group, but poor in the culture-positive group. If fungal keratitis is suspected, diagnostic KOH staining and culture tests should be performed initially. Early intensive antifungal medical treatments are necessary for patients with risk factors for poor clinical outcomes.