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At least 37 records · Page 2Linked to original sources
PubMed2002

Reactivations of ocular toxoplasmosis after cataract extraction.

PURPOSE: To determine the risk of reactivation of ocular toxoplasmosis following cataract extraction. DESIGN: Retrospective case-control study. PARTICIPANTS: Out of 154 patients with ocular toxoplasmosis, 14 patients (15 eyes) who had undergone a cataract extraction and 45 age- and sex- matched controls without cataract were selected. INTERVENTION: A review of the medical records of 14 patients with ocular toxoplasmosis and cataract and 45 control patients with ocular toxoplasmosis but without cataract. The clinical records of the controls and patients were assessed for an identical 4-month period following the date of the cataract extraction in the index patients. MAIN OUTCOME MEASURES: Development of a new active retinal lesion within 4 months after cataract surgery in patients and age -and sex matched-controls. The presence of risk factors such as sex, congenital or postnatal acquisition of ocular toxoplasmosis, age at first clinical manifestation of ocular toxoplasmosis, total number of attacks per affected eye, type of cataract, age at the time of cataract surgery and the intervals between surgery and first clinical manifestation of ocular toxoplasmosis and between surgery and the last recurrence of ocular toxoplasmosis, as well as the use of antiparasitic medication during surgery, type and complications of surgery and optimal visual acuity before and after cataract surgery. RESULTS: Reactivations of ocular toxoplasmosis following cataract extraction occurred in 5/14 patients (5/15 eyes), which was higher than the incidence of recurrences in age -and sex-matched controls (p < 0.001). No additional risk factors for the development of recurrences of ocular toxoplasmosis after cataract surgery were found. Incidence of recurrences preceding surgery did not differ between patients and controls. CONCLUSION: We identified an increased risk of reactivation of ocular toxoplasmosis following cataract extraction which implies that prophylactic treatment with antiparasitic drugs during and after the cataract surgery might be worthwhile for patients at risk of visual loss.

Adolescent↗
PubMed1993

[Treatment of ocular toxoplasmosis. Part 1: Basic principles and diagnosis].

Ocular toxoplasmosis is a frequent cause of ocular inflammation which threatens central visual acuity. New concepts of treatment are important alternatives for the well known therapy with pyrimethamine and sulphadiazine. They cause less side effects and result in better compliance. Up to know prospective randomized trials are still missing although they might prove the value of medical treatment in ocular toxoplasmosis. Nevertheless it is generally accepted that ocular toxoplasmosis should be treated when central visual function is threatened. Treatment strategy is influenced by general symptoms, especially in children and immunocompromised patients. In this paper opportunities for treatment are discussed. Relevant microbiological, immunological and epidemiological fundamentals are mentioned as well as serological tests.

Clindamycin↗
PubMed1980

Unusual presentation of acute ocular toxoplasmosis.

Two unusual cases of ocular toxoplasmosis are presented. A 24 year old woman developed retinal and optic nerve neovascularization in conjunction with acute ocular toxoplasmosis. The neovascularization regressed with resolution of the inflammation. The possibility of retinal ischemia or inflammation alone as an etiology are discussed. A 19 year old woman developed optic nerve edema and a marked decrease in vision associated with a nasal toxoplasma lesion and a macular star. With resolution of the process, optic atrophy developed but visual acuity returned to normal. Optic nerve edema and atrophy were felt to result from diffuse inflammation, but not from focal involvement in the nerve itself with the organism.

Adult↗
PubMed1995

Angiographic findings in eyes with active ocular toxoplasmosis.

Clinical findings in 5 cases of active ocular toxoplasmosis were documented by fluorescein angiography. The diagnosis was based upon the ophthalmoscopic findings of white, fluffy, retinal exudative lesions with or without overlying vitreous inflammatory cells, and positive serologic tests for toxoplasma and responsiveness to clindamycin therapy. Three cases were considered as recurrent ocular toxoplasmosis and the other 2 cases, acquired ocular toxoplasmosis. Angiographic characteristics of these 5 cases of acute ocular toxoplasmosis consisted of the following: 1) hypofluorescence in the center of the hyperfluorescent lesion, 2) black silhouette of the artery corresponding to the arterial occlusion traversing the necrotic lesion, 3) venous dilation, venous wall staining and dye leakage from the vein, 4) optic disc staining and dye leakage. These angiographic findings reflect either tissue necrosis or hypersensitivity reaction and are helpful in the correct and prompt diagnosis of acute ocular toxoplasmosis.

Adolescent↗
PubMed1992

Fuchs' heterochromic iridocyclitis is not associated with ocular toxoplasmosis.

To analyze the association between Fuchs' heterochromic iridocyclitis (FHI) and toxoplasmosis, we performed ocular examinations and used various specific laboratory tests to establish a role for Toxoplasma gondii in the pathogenesis of FHI. Results were compared with those for other types of uveitis and healthy controls. Of the 88 patients with FHI, nine (10.2%) had toxoplasmosislike scars, but an association could not be proved by the indirect immunofluorescence antibody test or enzyme-linked immunosorbent assay, or by a test for cellular immunity to Toxoplasma antigen. Analysis of aqueous humor samples for Toxoplasma antibodies in patients with FHI also yielded negative results. On the basis of the negative results of these laboratory tests, we concluded that FHI is not associated with ocular toxoplasmosis.

Adolescent↗
PubMed2001

Characterization of Toxoplasma gondii-specific T cells recovered from vitreous fluid of patients with ocular toxoplasmosis.

PURPOSE: The mechanisms involved in reactivations of latent ocular Toxoplasma gondii (Tg) infections in immunocompetent patients are poorly understood. In view of the possible role of T cells in the immunopathogenesis of the disease, ocular infiltrating T cells obtained from patients with recurrent ocular toxoplasmosis were characterized phenotypically and functionally. METHODS: Ocular infiltrating T cells were recovered from vitreous fluid (VF) samples of 10 patients with active recurrent ocular toxoplasmosis. Two patients with uveitis of other origins were included as control subjects. T-cell lines (TCLs) were generated by mitogenic stimulation and tested for reactivity to Tg and human retinal protein extracts. The TCLs of three patients were cloned by limiting dilution. Tg-reactive T-cell clones (TCCs) were characterized with respect to their phenotype, T-cell receptor variable (TCR V)-beta gene usage, HLA restriction, and cytokine secretion profile. RESULTS: Reactivity to Tg could be detected only in the TCLs of patients with ocular toxoplasmosis. None of the TCLs showed reactivity to human retinal antigens. All tested intraocular Tg-specific TCCs (n = 23) were CD3+CD4+ and displayed differential TCR Vbeta usage. Twenty-one TCCs were HLA-DR restricted and two TCCs were restricted by HLA-DP. The majority of the intraocular Tg-specific TCCs showed a bias toward a T-helper (Th)0-Th2 cytokine profile. CONCLUSIONS: The data indicate that T cells specific for the triggering microorganism infiltrate the eye of patients with recurrent ocular toxoplasmosis. The functional characteristics of the VF-derived Tg-specific T cells and their presence at the site of inflammation suggest their involvement in the local inflammatory response of ocular toxoplasmosis.

Adult↗
PubMed1992

An unusually high prevalence of ocular toxoplasmosis in southern Brazil.

Because of the frequency of ocular toxoplasmosis and its occurrence in multiple siblings in southern Brazil, a population-based household survey was performed to better understand the epidemiologic characteristics of the disease in this region. Of 1,042 individuals examined, 184 (17.7%) were deemed to have ocular toxoplasmosis on the basis of conservative assessment of ophthalmic findings. Of those with ocular toxoplasmosis, 183 (99.5%) had specific IgG antibodies, compared with only 140 of 181 age-matched control subjects (77.4%; P less than .001). The prevalence of ocular toxoplasmosis was 0.9% in 1- to 8-year-olds, 4.3% in 9- to 12-year-olds, 14.3% in 13- to 16-year-olds, and 21.3% (95% confidence interval, 18.6% to 24.2%) in all individuals 13 years or older. The prevalence of ocular toxoplasmosis in this population was more than 30 times higher than previous estimates for the same condition elsewhere. The low prevalence in the young children we studied supplements previous data suggesting that, in this population, ocular toxoplasmosis is a sequela of postnatal rather than congenital infection.

Adolescent↗
PubMed1986

Serology in ocular toxoplasmosis.

The diagnostic value of toxoplasma serology in ocular disease was evaluated in the following groups of patients: (I) uveitis cases of various causes (n = 291); (II) consecutive posterior and panuveitis patients (n = 60); (III) patients with definite congenital and ocular toxoplasmosis (n = 8); (IV) cases of clinical ocular toxoplasmosis (n = 25); and control patients with uveitis of non-toxoplasma origin (n = 12). No relation was observed between the level of the dye test titres and the diagnosis of ocular toxoplasmosis (groups I and II). During the active stages of the disease no typical change of the titres occurred in several longitudinally studied patients with toxoplasmosis. In group III one case was discovered to be negative by the dye test despite active ocular disease; however, IgG antibodies against toxoplasma were detected by the ELISA technique. In group IV, which was investigated by the ELISA technique, 100% of the toxoplasmosis patients were positive for IgG versus 58% of the control patients. Circulating immune complexes containing IgG and toxoplasma antigen were detected in seven of 25 toxoplasmosis patients (28%) and in two of 12 control patients (16%). Our study shows that the definite diagnosis of ocular toxoplasmosis or its exclusion by serological means only is not yet feasible. The possible superiority of the ELISA test to the dye test warrants further investigation.

Adolescent↗
PubMed1990

[Ocular toxoplasmosis in patients with acquired immunodeficiency syndrome].

Ocular toxoplasmosis is an uncommonly reported complication in patients with acquired immunodeficiency syndrome. Three patients with human immunodeficiency virus (HIV) infection and ocular toxoplasmosis are reported. In two of them, cerebral toxoplasmosis was associated. Ocular involvement presented as exudative chorioretinitis, bilateral in 2 cases and unilateral in 1. The diagnosis was made on the basis of ocular disease associated with lesions consistent with toxoplasmosis of central nervous system (CNS) and response to antitoxoplasma treatment in one case, and ocular disease with rising antitoxoplasma serologic titers in the remaining two. Initial therapy included pyrimethamine plus sulfadiazine in 2 cases and pyrimethamine plus clindamycin in 1. The 2 patients treated with sulfadiazine showed hypersensitivity features, and clindamycin had to be substituted. The response to therapy was favorable, although one patient died few days after the development of CNS lesions. When chorioretinitis develops in a patient with HIV infection, ocular toxoplasmosis should be considered. As CNS involvement is commonly associated and relapse after the withdrawal of therapy is likely, these patients should be treated as those with isolated toxoplasma encephalitis.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Differences between intraocular and serum antibody responses in patients with ocular toxoplasmosis.

PURPOSE: To investigate the antigen specificity of the intraocular anti-Toxoplasma gondii antibody response in patients with ocular toxoplasmosis. METHODS: Paired ocular fluid and serum samples were collected from 13 patients with active ocular toxoplasmosis. Serum IgM anti-T. gondii antibodies were tested to distinguish recently-acquired from chronic infection. Anti-T. gondii IgG specificity was analyzed by immunoblotting using a crude T. gondii extract. RESULTS: Two of the 13 patients tested were IgM positive and considered to have acquired ocular toxoplasmosis. The antibody specificity in ocular fluid and serum of these two patients was similar, whereas in the patients with presumed chronic disease, marked differences could be observed. Most ocular fluid samples contained antibodies that stained a 28-kD antigen more intensely than did antibodies from paired serum samples. Using absorption and elution experiments, we demonstrated that this 28-kD protein was identical to the GRA-2 antigen, which is expressed in both the tachyzoite and the bradyzoite stages of the parasite. CONCLUSIONS: Our results show that the intraocular T. gondii antibody response of patients with recurrent ocular toxoplasmosis differs from the systemic response. This finding may have implications for our understanding of the immunopathogenesis of ocular toxoplasmosis and could be employed to improve diagnosis of the disease.

Adult↗
PubMed1999

Serologic evaluation of patients with primary and recurrent ocular toxoplasmosis for evidence of recent infection.

PURPOSE: To identify the frequency of recently acquired vs chronic systemic Toxoplasma gondii infections in patients with ocular toxoplasmosis. METHODS: Serum samples from 22 patients with primary ocular toxoplasmosis (not from scars) and 42 patients with recurrent ocular toxoplasmosis were tested for the presence of anti-T. gondii IgM, IgG, and IgA antibodies and compared with samples from 24 patients with other causes of uveitis. Intraocular production of anti-T. gondii IgG and IgA, and the presence of T. gondii DNA was determined in patient s and control subjects from whom ocular fluid was available. RESULTS: Serologic evidence of recently acquired infection was found for 11 (50%) of 22 patients with primary ocular toxoplasmosis and for one (2%) of 42 with recurrent ocular toxoplasmosis. In the uveitis control group, anti-T. gondii IgM antibodies could be detected in two (8%) of 24 patients, but anti-T. gondii IgA antibodies were not detectable. Patients with primary ocular toxoplasmosis and serologic markers of recently acquired systemic infection were significantly older than those with chronic infection (P = .008). Intraocular production of anti-T. gondii IgG was more frequently noted in patients with recurrent than primary ocular toxoplasmosis (81% vs 41%; P < .001), but intraocular T. gondii DNA was more frequently found in patients with primary ocular toxoplasmosis than in those with recurrent ocular toxoplasmosis (37% vs 4%; P < .01). CONCLUSIONS: Primary ocular toxoplasmosis can be seen in either recently acquired or chronic T. gondii infection. Patients with ocular disease and recently acquired infection were older and more likely to have T. gondii DNA in intraocular fluids.

Adolescent↗
PubMed1984

The macula in ocular toxoplasmosis.

Of 60 attacks of ocular toxoplasmosis, in 37 (62%) no apparent macular problems were demonstrated on inspection, in seven (12%) active retinitis was evident within 5 degrees of the umbo, and in seven (12%) some evidence was shown of mild macular edema; severe edema, such as cystoid macular edema, was uncommon.

Anterior Chamber↗
PubMed1998

[Current limits in diagnosis of ocular toxoplasmosis].

BACKGROUND: The diagnosis of ocular toxoplasmosis has remained a merely clinical one, because the low sensitivity of established methods does not allow clinical consequences. The underlying open prospective study was undertaken to analyse the sensitivity of a combination including the newly available tests for the diagnosis of the disease. METHODS: From 27 patients included until now, aqueous humor and serum samples were collected and sent to one of two reference laboratories according to their actual availability. From all samples, total IgG and anti-Toxoplasma IgG as well as specific IgM and IgA were quantified, and from the results, the antibody ratio was calculated according to the formula of Goldmann and Witmer. From the samples sent to laboratory 2, antibody avidity was determined and Toxoplasma DNA amplified using PCR. RESULTS: A confirmation of the clinical diagnosis was achieved in 5/9 cases (56%) from samples sent to laboratory 1, and from 14/18 samples (78%) sent to laboratory 2. Calculation of the antibody ratio was confirmed to be the most sensitive method with a confirmation rate of 41%, followed by PCR (28%), determination of specific IgA (22%) and finally antibody avidity (15%). A confirmation with two independent tests was achieved in 28% of cases. CONCLUSION: None of the methods analysed was sensitive enough to establish the diagnosis in a given case. The combination of all four methods, however, achieved a sensitivity, which is high enough to justify a clinical routine analysis of aqueous humor samples.

Animals↗
PubMed1999

The relationship between ocular toxoplasmosis and levels of specific toxoplasma antibodies.

The relationship between ocular toxoplasmosis and levels of toxoplasma specific antibodies was examined in 195 patients. Using clinical information collected by questionnaires, patients were divided into: 97 with ocular toxoplasmosis (group 1) and 98 with ocular lesions not due to toxoplasma (group 2). The geometric mean of dye test titres (+/-S.D. natural log titre) in group 1 was 53.2 (+/-0.95) compared with 24.6 (+/-1.11) in group 2 (P < 0.001). Young females tended to have more active lesions compared with young males (P < 0.05). There was an age-dependent difference in dye test titres between the groups (P < 0.001). Group 1 showed a decline in titre with age compared with an increase in group 2. Ocular toxoplasmosis was diagnosed most frequently among 21-30 year olds. More group 1 patients had dye test titres > or = 65 iu/ml than group 2 (P < 0.05). Dye test titres > or = 65 iu/ml support a diagnosis of ocular toxoplasmosis whereas lower titres suggest other causes for eye lesions.

Adolescent↗