Rapid diagnosis of fungal keratitis in patients with corneal ulcer using Calcofluor White stain

Document Type : Original Article


1 Clinical Pathology Department, Faculty of Medicine, Ain Shams University, Egypt

2 Ophthalmology department, Faculty of medicine, Ain Shams University, Cairo, Egypt


Background: The prevalence of fungal keratitis has risen in recent years significantly. To avoid additional complications, diagnosing and treating fungal keratitis is crucial. This study aims to measure the efficacy of a calcofluor white (CFW) stain for the quick diagnosis of fungal keratitis and to contrast the positive rates, sensitivity, and specificity with a 10% potassium hydroxide (KOH)-based smear and culture technique. Methods:From individuals with clinically suspected corneal ulcers, 30 corneal scrapings had been collected. Data on demographics had been analyzed. Results: Of the 30 patients, 40% were women and 60% were men. There was a 1.5:1 man-to-woman ratio. The age of patients ranged from 29 to 71 years (mean 46.67 ± 10.90). The age presentation of those between the ages of 41 and 50 years was the most frequent (36.7%). The majority of cases were farmers (43.3%). Trauma was the most common predisposing factor (46.6%). Twenty-four (80%) cases were culture positive. Eleven (36.7%) were fungal, 13 (43.3%) were bacterial and 6 (20%) showed no growth. Fusarium was the most common fungal isolate (36.4%), followed by Aspergillus (27.3%). While Staphylococcus aureus was the most common bacterial isolate (46.2%), followed by Pseudomonas (38.4%). The sensitivity of KOH wet mount and CFW stain was 72.7% and 90.9%, respectively. The specificity of both KOH wet mount and CFW stain was 100%. Conclusion:The early diagnosis of fungal keratitis can be made rapidly by direct microscopic examination of fungal elements using CFW stain. When diagnosing fungal keratitis, CFW has higher sensitivity to KOH.


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