Culture positivity of anterior chamber exudate in cases of fungal keratitis.

Abstract

Purpose: To describe the nature of anterior chamber (AC) exudates in cases of fungal keratitis, and to determine whether these are inflammatory or infective.

Methodology: Twenty-six patients with culture-proven fungal keratitis and anterior chamber exudate, worsening due to medical management and who underwent therapeutic penetrating keratoplasty (TPK), were included in the study. Patients with mixed infections, prior surgical intervention, perforation, or absence of hypopyon/AC exudates were excluded from the study. AC exudates were plated on one/two solid culture media during surgery after excision of the corneal button. The corneal buttons were bisected into half and sent for microbiological and histopathological examinations.

Results: Among the 26 patients, 14 were male, and most of them were farmers. Most patients (73%) had a history of trauma with vegetative matter and presented within 17.8 ± 11.7 days from the appearance of the first symptom. All patients had visual acuity less than counting fingers at 2 m. Corneal scraping confirmed fungal keratitis in all patients, with Aspergillus flavus (57.7%) being the predominant species. Despite medical treatment, all patients worsened and required TPK within a fortnight. Samples from AC exudates grew fungus only in 4/26 (15.4%) cases, and the bisected corneal buttons grew fungus in 7/26 (26.9%). Histopathology revealed fungal filaments in all samples, with 19 (79.2%) cases involving the posterior stroma and Descemet's membrane.

Conclusion: AC exudates in fungal keratitis are usually sterile if there is no perforation or prior intervention, and therefore, most of the AC exudates were inflammatory.