
Full text loading...
Category: Fungi and Fungal Pathogenesis
Ocular Microsporidiosis, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555818227/9781555811471_Chap09-1.gif /docserver/preview/fulltext/10.1128/9781555818227/9781555811471_Chap09-2.gifAbstract:
One of the difficulties in understanding the epidemiology of ocular microsporidiosis is the constantly changing nomenclature and the difficulty in speciation. The clinical and histopathologic appearance of ocular microsporidiosis can be divided into two distinct patterns of infection, one involving the deep corneal stroma and seen in immunocompetent patients, and the other a superficial epithelial keratopathy infection seen in immunodeficient individuals. Both deep stromal and superficial epithelial keratitides due to ocular microsporidiosis are rare but must be considered in situations where these entities do not respond to conventional therapy. Ocular microsporidiosis has emerged as the cause of bilateral keratoconjunctivitis in immunosuppressed individuals. The differential diagnosis of microsporidial infection causing stromal disease is broader; diagnosis is unlikely based on clinical examination. Microsporidia are sufficiently unique to be classified as a separate phylum. The early light microscopy (LM) findings of ocular microsporidiosis were instrumental in localizing and recognizing these organisms in other tissues. Both isolated, deep stromal keratitis and superficial epithelial keratitis caused by microsporidia are rare. However, superficial keratitis is important, as it may be the initial manifestation of systemic microsporidia infection. Therapy, either topical or systemic, can be visually and pathologically evaluated with minimal morbidity.
Full text loading...
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 ].)
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 ].)
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 ].)
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 ].)
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 ].)
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 ])
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 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.
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.)
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. 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.)
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 ].)
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 ].)
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.)
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.)
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.)
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.)
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.)
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.)
Cases of ocular microsporidial infection in immunocompetent patients
Cases of ocular microsporidial infection in immunocompetent patients
Cases of ocular microsporidial infection in immunosuppressed patients
a N.S.,not stated.
b Number of cases included but previously reported.
Cases of ocular microsporidial infection in immunosuppressed patients
a N.S.,not stated.
b Number of cases included but previously reported.