A Comparative Study of Potassium Hydroxide Wet Mount, Calcofluor White Staining and Culture for the Diagnosis of Keratomycosis

Background: The incidence of keratomycosis has increased dramatically in recent years. Early diagnosis and treatment of keratomycosis are important in preventing further complications. Direct microscopic techniques are time-saving for diagnosing keratomycosis when compared to culture methods. This study was carried out to determine the sensitivities of potassium hydroxide (KOH) wet mount, Gram stain and Calcofluor white (CFW) stain plus KOH wet mount by taking culture as the gold standard. The positivity of CFW stain plus KOH wet mount, KOH wet mount, and Gram stain was 30%, 23.3%, and 20%, respectively. Sensitivities of CFW stain plus KOH wet mount, KOH wet mount, and Gram stain were 79.55%, 54.55%, and 47.62%, respectively. Conclusion: Post-investigative analysis has revealed that CFW stain plus KOH wet mount was better than KOH wet mount alone in demonstrating fungal pathogens. Therefore, early diagnosis of keratomycosis by meticulous examination of corneal scrapings by direct microscopy specifically using CFW stain plus KOH wet mount and institution of antifungal therapy may limit ocular morbidity and disastrous sequelae among these patients.