Ocular toxoplasmosis II: Clinical features, pathology and management
Division of Ocular Immunology, Wilmer Eye Institute, Johns Hopkins School of Medicine Clinical and Experimental Ophthalmology
(Impact Factor: 2.35).
06/2012; 41(1). DOI: 10.1111/j.1442-9071.2012.02838.x
The term, ocular toxoplasmosis, refers to eye disease related to infection with the parasite, Toxoplasma gondii. Recurrent posterior uveitis is the typical form of this disease, characterized by unilateral, necrotizing retinitis with secondary choroiditis, occurring adjacent to a pigmented retinochoroidal scar and associated with retinal vasculitis and vitritis. Multiple atypical presentations are also described, and severe inflammation is observed in immunocompromised patients. Histopathological correlations demonstrate focal coagulative retinal necrosis, and early in the course of the disease, this inflammation is based in the inner retina. For typical ocular toxoplasmosis, a diagnosis is easily made on clinical examination. In atypical cases, ocular fluid testing to detect parasite DNA by polymerase chain reaction or to determine intraocular production of specific antibody may be extremely helpful for establishing etiology. Given the high seroprevalence of toxoplasmosis in most communities, serological testing for T. gondii antibodies is generally not useful. Despite a lack of published evidence for effectiveness of current therapies, most ophthalmologists elect to treat patients with ocular toxoplasmosis that reduces or threatens to impact vision. Classic therapy consists of oral pyrimethamine and sulfadiazine, plus systemic corticosteroid. Substantial toxicity of this drug combination has spurred interest in alternative antimicrobials, as well as local forms of drug delivery. At this time, however, no therapeutic approach is curative of ocular toxoplasmosis. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.
Available from: Pilar Nannini
- "Substantial toxicity of this drug combination has spurred interest in alternative antimicrobials, as well as local forms of drug delivery. At this time, however, no therapeutic approach is curative of ocular toxoplasmosis  "
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ABSTRACT: Infection with the protozoan Toxoplasma gondii is one of the most frequent parasitic infections worldwide and the common infection of the retina in the general population. We describe a case report of a chorioretinitis in an immunocompetent 8-year-old patient as a consequence of a underdiagnosed neonatal toxoplasmosis. The boy was successfully managed with pyrimethamine and sulfadiazine. The present case we would like to empathize the importance of considering toxoplasma gondii as a possible cause of chorioretinitis in children living in developed countries and we provide a detailed reviewed of the literature about treatment of Toxoplasma gondii infection.
Available from: Tsutomu Sakai
- "Ocular manifestations associated with toxoplasmosis may be caused by an active infection or an immunologic reaction in the absence of any infectious agent.1 Our case presented with CRAO with optic disc involvement and multifocal retinitis with perivascular sheathing as a primary manifestation, in contrast to cases with this condition diagnosed as a secondary manifestation to preexisting retinochoroiditis. "
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ABSTRACT: Central retinal artery occlusion (CRAO) and multifocal retinitis with perivascular sheathing are rare in ocular toxoplasmosis. We report a case of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. A healthy 83-year-old male developed left panuveitis. Funduscopic examination of the left eye showed a swollen optic disc and sheathing of the retinal artery with a dense vitreous haze and a white retinal lesion. Serum anti-toxoplasma antibodies were positive in a latex agglutination assay. Vitrectomy was performed to improve visualization of the retinal lesions and for examination of causative microorganisms. A postoperative fundus examination revealed CRAO with optic disc involvement and multifocal retinitis with perivascular sheathing. Qualitative multiplex polymerase chain reaction detected the Toxoplasma gondii B1 gene in ocular fluid from both the aqueous and vitreous humor. The presumed diagnosis of ocular toxoplasmosis was made and treatment was started with prednisone and acetylspiramycin with subsequent improvement. Two months later, the patient developed active retinochoroiditis in the left eye. After 6 weeks of anti-toxoplasma therapy, the disease involuted. Retinal vascular occlusions and multifocal retinitis with perivascular sheathing are rare in toxoplasmosis. This is the first case report of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. The diagnosis of ocular toxoplasmosis should be considered in patients with retinal artery occlusions and multifocal retinitis with perivascular sheathing associated with inflammation.
Available from: Anilton Vasconcelos
- "Toxoplasmosis causes destructive inflammation that targets multiple organs, including the eyes. Only a few infected individuals develop ocular lesions or toxoplasmic retinochoroiditis (TR) (Holland, 2003; Butler et al., 2013). TR is the most common identifiable cause of posterior uveitis in many parts of the world (Henderly et al., 1987; Furtado et al., 2013). "
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ABSTRACT: This study evaluated the morphometric implications in C57BL/6 mouse retina infected by Toxoplasma gondii, ME 49 strain. Twenty C57BL/6 female mice were divided into group 1 (n=8, intraperitoneally infected with 30 cysts of T. gondii ME 49 strain) and group 2 (n=12 non-infected controls). The eyes were enucleated on the 60(th) day after infection, fixed and processed for light microscopy. Changes in retinal thickness and in the perimeter/area ratio (P/A) of the retinal layers were analyzed by digital morphometry. We considered that P/A was the measurement of retinal architecture distortion induced by toxoplasmosis. This study considered the ganglion cells and nerve fiber layers as a monolayer, thus six layers of retina were evaluated: photoreceptors (PRL), outer nuclear (ONL), outer plexiform (OPL), inner nuclear (INL), inner plexiform (IPL) and ganglion cells/nerve fiber monolayer (GNL). Histological analysis of infected mouse retina showed inflammatory infiltrate, necrosis, glial reaction and distortion of the retina architecture. It also presented increased thickness (167.8 ± 24.9 μm versus 121.1 ± 15.4 μm, in controls) and increased retinal thickness within the retinitis foci (187.7 ± 16.6 μm versus 147.9 ± 12.2 μm out of the retinitis foci). A statistically significant difference in P/A was observed between infected and uninfected mouse retinas. The same was observed in PRL, OPL, INL and GNL. Retinal morphometry may be used to demonstrate differences between infected and uninfected mouse retinas.
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