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Infiltrative Optic Neuropathies
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Aniruddha Agarwal, Sabia Handa, Vishali Gupta
Ocular toxoplasmosis is one of the most frequent etiologies of infectious posterior uveitis. This condition is caused by the obligate intracellular protozoan parasite Toxoplasma gondii. Ocular involvement in toxoplasmosis may result from acquired infection after birth or from the congenital form of the disease. The classical presentation of the disease is a focus of inner retinitis adjacent to an old chorioretinal scar accompanied by dense focal vitritis (headlight in fog appearance).95–97
Aicardi Syndrome and Klinefelter Syndrome
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
Differential diagnoses for Aicardi syndrome include (i) microcephaly with or without chorioretinopathy, lymphedema, or mental retardation (MCLMR, in which chorioretinal changes do not involve peripheral and optic nerves, and neuronal migration defects are uncommon, whereas chorioretinal lacunae in Aicardi syndrome are central and involve the optic nerves, and neuronal migration defects are almost universal); (ii) oculocerebrocutaneous syndrome (OCCS, which may display orbital cysts and anophthalmia or microphthalmia, focal skin defects, polymicrogyria, periventricular nodular heterotopias, enlarged lateral ventricles, and agenesis of the corpus callosum, but predominant in males); (iii) tuberous sclerosis complex and Rett syndrome (which also shows infantile spasms); (iv) orofaciodigital syndrome type IX (OFD 9, which may show chorioretinal lacunae); (v) Goltz syndrome and microphthalmia with linear skin defects syndrome (which also have microphthalmia and other developmental eye defects, but differ from Aicardi syndrome by their characteristic skin defects and other features); (vi) Dandy−Walker syndrome, agenesis of the corpus callosum, neuronal migration disorders, Lennox−Gastaut syndrome, lissencephaly, West syndrome, and cyclin-dependent kinase-like 5 disorder, all of which may display seizure; and (vii) ocular toxoplasmosis (showing small or peripheral lacunae) [10].
Infections
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
Ocular toxoplasmosis occurs after congenital toxoplasmosis, or as a reactivation in immunocompromised hosts. The retina and choroid are mainly involved, causing blurred vision and pain. There is acute retinal necrosis.
Ocular Toxoplasmosis Associated Dark Without Pressure
Published in Ocular Immunology and Inflammation, 2023
Paul J. Steptoe, Catherine M. Guly, Andrew D. Dick
Ocular toxoplasmosis occurs secondary to a retinal infection by Toxoplasma gondii, an obligate intracellular protozoan parasite.1 Typical ocular toxoplasmosis lesions are characterised by a unilateral, focal retinal lesion, which is usually described as necrotising retinitis2,3 and account for over 90% of presentations.4 The term dark without pressure (DWP) was originally coined by Nagpal et al. to describe homogeneous, geographical, flat, brown areas on the fundus5 and correspond to a thinned, hyporeflective ellipsoid zone band on optical coherence tomography (OCT).6–8 While most commonly seen in isolation5–7 and of unknown aetiology, their perilesional association with infective aetiology has been reported in recent studies of Ebola virus disease (EVD) retinal lesions.8,9 In EVD survivors, areas of DWP were also observed adjacent to lesions typical of ocular toxoplasmosis and in one patient observed to slowly expand over a 12-month observation (Figure 1).8 Here, we report a case further highlighting fluctuations of DWP associated with ocular toxoplasmosis reactivation.
Molecular diagnosis of toxoplasmosis: recent advances and a look to the future
Published in Expert Review of Anti-infective Therapy, 2021
Marie Gladys Robert, Marie-Pierre Brenier-Pinchart, Cécile Garnaud, Hélène Fricker-Hidalgo, Hervé Pelloux
Immunocompromised patients are particularly at risk of severe and potentially fatal toxoplasmosis, which results mainly from the reactivation of a chronic infection and more rarely from a primary infection or, in the case of solid organ transplant, from the transmission of T. gondii encysted in the graft from a seropositive donor to a seronegative recipient. Various clinical presentations may be encountered, with the most frequent being cerebral, pulmonary or disseminated toxoplasmosis [9]. These urgent situations require immediate treatment and therefore a quick diagnosis. However, serological tests may lack sensitivity in this population. Direct diagnostic techniques are of great interest. Among them, molecular diagnosis is an essential option as it is sensitive and fast. Its effectiveness is, however, relatively difficult to evaluate in the particular context of toxoplasmosis in an immunocompromised patient, because the definitive diagnosis is often based on a combination of clinical and paraclinical arguments [47]. Nevertheless, in a recent review of the practice in 11 European countries regarding toxoplasmosis in transplant recipients, PCR has been shown to be the most useful diagnostic tool, surpassing imaging and serology [48]. The use of PCR in the diagnosis of cerebral, pulmonary and disseminated toxoplasmosis is discussed in the following paragraphs. Ocular toxoplasmosis is treated separately below as it also concerns immunocompetent patients.
Clinical, Socio-economic and Environmental Factors Related with Recurrences in Ocular Toxoplasmosis in Quindío, Colombia
Published in Ophthalmic Epidemiology, 2021
Stefany Velasco-Velásquez, Daniel Celis-Giraldo, Andrea Botero Hincapié, Diego Alejandro Hincapie Erira, Sara Sofia Cordero López, Nathalia Marulanda Orozco, Jorge Enrique Gómez-Marín
Surprisingly, consumption of boiled water was associated with a lower recurrence index (p = .042). This is the first evidence of the influence of boiled water consumption on the incidence of recurrences in ocular toxoplasmosis. This reinforces the hypothesis of the importance of waterborne transmission of Toxoplasma gondii.34,35 It has been established that the transmission route predisposes to severe forms of the disease.36 Accordingly, some authors have indicated a higher percentage of reactivation in times of high rainfall.20 This also raises questions about reinfections possibly increasing recurrences. Until now, reinfections were believed to come from an endogenous reactivation of dormant parasites obtained from old infections inside tissue cysts; however, reports exist of repeated congenital infection after reinfections.37,38 In ocular toxoplasmosis, reactivation related to new infection by other strains that promote eye damage cannot be ruled out. A similar phenomenon has been seen in reinfection or superinfection by Plasmodium spp. strains that predispose to more severe disease presentations.38,39 In this sense, one of the prevention strategies to avoid relapses may include, besides prophylactic treatment, recommendations for consumption of boiled or bottled water. Moreover, promotion of adequate sanitary water management with monitoring and follow up of the presence of these parasites in drinking water can be essential to reduce risks of infection or reinfections.40