Microsporidial keratitis retrospectively diagnosed by ultrastructural study of formalin-fixed paraffin-embedded corneal tissue: a case report

a Image of anterior segment before penetrating keratoplasty. Multiple corneal opacities showing crystalline keratopathy were observed. b Gram staining of the scraped cornea (×400 magnification). Although oval microorganisms were detected, they were not stained. c Fungiflora Y staining of the scraped cornea (×400 magnification). Oval microorganisms were visible under ultraviolet illuminatio