Silvany R E, Luckenbach M W, Moore M B
Department of Ophthalmology, University of Texas Health Science Center at Dallas, Southwestern Medical School 75235-9057.
Arch Ophthalmol. 1987 Oct;105(10):1366-7. doi: 10.1001/archopht.1987.01060100068028.
Acanthamoeba keratitis is a difficult diagnosis to make with routine stains and cultures. Gram's, Giemsa, and hematoxylin-eosin stains do not differentially stain Acanthamoeba, making the detection of organisms difficult. Trophozoite and cyst forms in paraffin-embedded corneal tissue sections can be rapidly and differentially stained with calcofluor white. Under the fluorescence microscope, the trophozoites are bright red-orange, and cyst cell walls fluoresce bright apple-green with red-orange cytoplasm. Retrospective identification can be made by destaining hematoxylin-eosin-stained sections. Digesting background corneal tissue with trypsin or collagenase and hyaluronidase solutions helps to more readily identify trophozoites.
