Chapter 9 : Ocular Microsporidiosis

Several keratocytes with ill-defined basophilic spores of V. corneae.The sample was stained with hematoxylin and eosin. Original magnification, Xl60.) (Reprinted with permission from Ophthalmology[ Davis et al., 1990 ].)

Same field as Fig. 1 with numerous birefringent linear structures probably corresponding to portions of polar filament. The sample was viewed by polarized light. Original magnification, x160. (Reprinted with permission from Ophthalmology[ Davis et al., 1990 ].)

Anterior corneal stroma. Many keratocytes contain gram positive spores, and some are extracellular. Corneal epithelium appears slightly thinned, and Bowman's layer appears intact. The sample was treated with Brown and Hopps stain. Original magnification, x100. (Reprinted with permission from Ophthalmology[ Davis e t al., 1990 ].)

High-power view of area in Fig. 3 showing both intracellular and extracellular organisms. The sample was treated with Brown and Hopps stain. Original magnification, x252. (Reprinted with permission from Ophthalmology[ Davis et al., 1990 ].)

Organisms are acid fast variable. The sample was treated with Ziehl- Neelsen stain. Original magnification ×252. (Reprinted with permission from Ophthalmology [ Davis et al., 1990 ].)

Oval to elongated extracellular spores are outlined within the corneal stroma.The sample was treated with Grocott methenamine-silver stain. Original magnification, ×403. (Reprinted with permission from Ophthalmology [ Davis et al., 1990 ])

Conjunctival scraping with numerous large ovoid gram positive organisms within conjunctival epithelial cells. Original magnification, ×500. (Reprinted with permission from Archives of Ophthalmology [ Friedberg et al., 1990 ]. Figure copyright 1990, American Medical Association.)

Conjunctival scraping showing organisms staining with Giemsa stain. Original magnification, ×500.

Plastic section of conjunctival biopsy specimen. Sloughing superficial cells contain parasite-laden vacuoles. Mature spores stain densely. The sample was treated with methylene blue-azure II-basic fuchsin stain. Original magnification, ×360. (Reprinted with permission from Archives of Ophthalmology [ Friedberg et al., 1990 ]. Figure copyright 1990, American Medical Association.)

Electron micrograph from conjunctival biopsy. A mature electron-dense uninucleate spore has seven turns of the polar tubule. Original magnification, ×46,000. (Reprinted with permission from Archives of Ophthalmology [ Friedberg et al., 1990 ). Figure copyright 1990, American Medical Association.)

Electron micrograph from conjunctival biopsy. The superficial cell has clear parasitophorous vacuoles with parasites at various stages of development. Deeper cells show meronts in vacuole indenting the nucleus (lower right). Original magnification, ×2,700. (Reprinted with permission from Archives of Ophthalmology [ Friedberg et al., 1990 ]. Figure copyright 1990, American Medical Association.)

Stromal keratitis from Vittaforma corneae.(Reprinted with permission from Ophthalmology [ Davis etal.,1990 ].)

Eye in Fig. 12 six months after corneal transplantation. There is no evidence of recurrent microsporidial keratitis. ( Reprinted with permission from Ophthalmology [ Davis et al., 1990 ].)

Minimal bulbar conjunctival reaction with moderate hyperemia of inferior palpebral conjunctiva with erythema and fusiform edema in the inferior fornix of an AIDS patient infected with Encephalitozoon hellem.(Reprinted with permission from Archives of Ophthalmology [ Friedberg et al., 1990 ]. Figure copyright 1990, American Medical Association.)

Mild superficial epithelial keratitis in AIDS patient infected with E. hellem. (Reprinted with permission from Archives of Ophthalmology [ Friedberg et al., 1990 ]. Figure copyright 1990, American Medical Association.)

Diffuse, coarse, superficial epithelial keratitis in an AIDS patient infected with E. hellem. (Reprinted with permission from Archives of Ophthalmology [ Friedberg et al., 1990 ]. Figure copyright 1990, American Medical Association.)

Conjunctival scraping showing microsporidial organisms reacting intensely with species-specific antisera indicating presence of E. hellemin conjunctival epithelial cells. Original magnification, ×1,000.) (Reprinted with permission of the author and publisher from the American Journal of Ophthalmology [ Diesenhouse et al., 1993 ]. Figure copyright, Ophthalmic Publishing Co.)

In vivo confocal microscopy demonstrates corneal epithelial cells which contain intracellular microsporidial spores. (Inset) Enlargement of the two cells, showing numerous aggregates of small, high contrast intracellular microsporidial spores (arrows). (Micrograph courtesy of Gaurav Shah and Edward Holland.)