Microsporidial stromal keratitis with fungal co-infection

We report a case of simultaneous microsporidial and filamentous fungal co-infection presenting as stromal keratitis. A 52-year-old immunocompetent male presented with a chronic non-resolving corneal ulcer in the right eye, with a full-thickness stromal infiltrate and corneal perforation. Corneal scrapings evaluated using 10% potassium hydroxide with calcofluor white and Gram staining revealed oval microsporidial spores and septate hyaline fungal filaments. The patient was treated with hourly topical 1% voriconazole and 5% natamycin and oral ketoconazole. Given the corneal perforation and extensive stromal involvement, therapeutic penetrating keratoplasty was performed. The corneal button culture grew Aspergillus flavus , and histopathological examination confirmed the presence of fungal filaments and microsporidial spores. At one month, despite an initially clear graft, subsequent secondary graft failure required optical penetrating keratoplasty with cataract extraction. The final visual acuity was 20/80.