Search

Ocular toxocariasis (OT) is a zoonotic parasitic infection mainly caused by the intraocular tissue invasion of second-stage Toxocara canis or Toxocara cati larva. Measuring specific anti-T. canis antibodies in the intraocular fluid (IF) can increase OT diagnosis accuracy using Goldmann-Witmer coefficient (GWC). However, there is no systemic evaluation of GWC application in the immunological diagnosis of OT. To assess GWC for the immunodiagnosis of ocular toxocariasis, paired IF and serum samples from 72 patients diagnosed with OT were retrospectively analyzed for specific anti-T. canis IgG by enzyme linked immunosorbent assay (ELISA). GWC values were calculated to determine intraocular specific IgG production. Clinical features and other laboratory data were recorded, and their correlations with GWC evaluated. Of the 72 OT patients, 60 (83.33%) showed intraocular specific IgG production confirmed by GWC, while intraocular nonspecific IgE production was found in 64/69 (92.75%) cases. No significant correlation was found among clinical features and IF specific IgG production. Values for peripheral blood samples were lower than those of intraocular fluid regarding OT screening, and vitreous humor samples showed increased local specific IgG and nonspecific IgE production compared with aqueous humor samples. Overall, our results indicate that GWC and intraocular IgE production have referential values in diagnosing ocular toxocariasis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Purpose: To report a rare case of bilateral ocular toxocariasis with a different clinical presentation in each eye., Case Report: A 56-year-old man presented with severe ocular pain and acute visual loss in the right eye (RE). His best-corrected visual acuity was hand motion in the RE and 20/30 in the left eye (LE). Slit-lamp examination showed a severe anterior chamber reaction in the RE and a moderate anterior chamber reaction in the LE. The fundus of the LE showed a posterior hemorrhagic granuloma with vascular sheathing whereas the fundus of the RE was not visible because of severe vitreous opacification. Blood laboratory testing disclosed hyperproduction of IgE but no eosinophilia. Serum enzyme-linked immunosorbent assay testing was positive for Toxocara canis IgG (1:38). Toxocara antibody was also detected in the aqueous humor from both eyes (RE, 1:321; LE, 1:254). The patient was treated with topical and oral steroids along with oral albendazole. Additionally, phacoemulsification, a therapeutic vitrectomy, and vitreous cultures were performed in the RE. During the vitrectomy, the fundus of the RE showed diffuse retinal vascular obstruction with sheathing. Toxocara antibodies were detected in the vitreous fluid from the RE (1:679). A laser barrier was placed around the granuloma in the LE. After 1 month of steroid therapy, a tapering schedule was started. At 6 months postoperatively, the fundi of both eyes were stable. The final best-corrected visual acuity was 8/20 in the RE and 20/20 in the LE., Conclusions: A rare case of bilateral ocular toxocariasis is reported with a different clinical presentation in each eye that was diagnosed using enzyme-linked immunosorbent assay analysis of intraocular fluids. Both eyes were successfully treated medically with a vitrectomy eventually being required in the RE.

Purpose: Since few reports had been published on the prevalence of toxocariasis in ankylosing spondylitis (AS) patients with acute non-granulomatous anterior uveitis (ANGAU), the aim of this work was to determine the presence of antibodies against Toxocara canis in AS patients with ANGAU., Methods: Thirty-six patients (14 female and 22 male) with AS were enrolled in the study. The history of ANGAU was accepted only if diagnosed by an ophthalmologist. The detection of IgG antibodies to T. canis was determined by enzyme-linked immunosorbent assay. In addition, antibodies to Ascaris lumbricoides were also tested to verify non-specific reactions., Results: The prevalence of ANGAU in the AS patients was 58% (21 / 36), and 38% (8 / 21) of the patients with ANGAU were positive for antibodies to Toxocara, while 7% (1 / 15) of AS patients without ANGAU were positive for T. canis (p = 0.038, two tails; mid-p exact). No antibodies were detected to A. lumbricoides antigens in the serum samples of patients with AS., Conclusions: These data suggest that the seroprevalence of antibodies to T. canis is high in Mexican patients with AS-associated uveitis, suggesting a chronic asymptomatic toxocariosis, which could be associated with the pathogenesis of ANGAU; however, further larger-scale studies are needed to confirm this observation.

The aim of this study was to compare the performance of three in-house diagnostic tests, that is, histopathology, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR), for the diagnosis after experimental infection with Toxocara cati. Twenty Mongolian gerbils and Wistar rats were divided into ten groups (n = 2/group). Toxocara cati infections were established in Mongolian gerbils and Wistar rats by administering doses of 240 and 2500 embryonated Toxocara cati eggs by gavage, respectively. Tissue sections were stained with Haematoxylin and Eosin and observed under the light microscope. Sera and vitreous fluid collected from separate infected groups were tested against Toxocara cati antigens, for 92 days postinfection. Genomic DNA was extracted from formalin-fixed paraffin-embedded (FFPE) blocks, and aqueous fluids belong to the animals. The histopathology test gave negative results among the groups of animals examined between 5 and 92 days postinfection. The ELISA results showed that anti-Toxocara antibodies have risen between 7 and 61 days postinfection in sera and vitreous fluid in the animals infected, respectively. Analysis of PCR products revealed positive band (660 bp) in the orbital tissue infected Mongolian gerbils at 5 days postinfection. Of the three evaluated methods, the PCR could be recommended for scientific and laboratory diagnoses of toxocariasis in experimentally infected animals.

Ocular toxocariasis is prevalent among children. The symptoms and signs may mimic other ocular pathologies such as malignancies and other infectious diseases (such as toxoplasmosis and syphilis). We presented a case of progressive blurring of vision in a single eye of a 9-year-old boy. The presence of anti-toxocara antibody in serum samples helps to confirmation the diagnosis in our patient. Despite of treatment, the boy had lost his vision on the affected eye.

Human ocular toxocariasis is diagnosed using ophthalmologic and immunologic examinations. Many researchers have suggested that intraocular parasite-specific antibody levels are indicative of ocular toxocariasis, but little is known about the time course of the changes in these levels. We therefore investigated the anti-Toxocara canis antibody profile in the aqueous humor in an animal model of ocular toxocariasis. We intravitreally injected T. canis larvae into the right eye of 4 rabbits; 2 rabbits were orally administered T. canis eggs. We collected serum, aqueous humor, and tear samples weekly and determined the serum and aqueous humor levels of anti-T. canis immunoglobulin (Ig)G, IgA, IgM, and IgE antibodies and the tear IgG antibody level by enzyme-linked immunosorbent assay (ELISA). The severity of vitreous opacity and the aqueous humor IgG levels (measured using optical density [OD]) changed concordantly in the larvae-injected eyes; the OD exceeded 0.1 from 2-4 weeks after infection and remained elevated during active intraocular inflammation. However, the aqueous humor IgG levels were also elevated in 6 out of 8 eyes without intraocular larvae in both groups, and were low in 1 eye with live intravitreal larvae. In contrast, the serum IgG and IgM levels and the tear IgG levels increased in all rabbits, regardless of the presence of intraocular inflammation. Vitreous opacity occurred in all intravitreally infected eyes, but significant histopathological evidence of retinal damage was not detected. Thus, besides the presence of intraocular larvae, some other factors in the host may be required for the development of retinal lesions.

Purpose: To report the association of Fuchs heterochromic cyclitis (FHC) and ocular toxocariasis in a young adult., Design: Observational case report., Methods: A 26-year-old patient was referred for the management of a unilateral intermediate uveitis associated with a lower peripheral subretinal fibrotic lesion near the pars plana. Diagnosis of FHC was clinically confirmed. Laboratory examination was performed to exclude an infectious condition., Results: LISA assay detected significant levels of IgG directed against Toxocara canis. Toxoplasmic serology was negative, excluding this differential diagnosis. Other examinations, including complete blood cell count, urinalysis, serum angiotensin-converting enzyme, lysosyme, chest CT scan, and syphilis serology were noncontributive., Conclusions: Previous studies have reported on the association of FHC and other parasitic conditions, such as toxoplasmosis but also on herpetic ocular infections. Serologic analysis for toxocariasis may be proposed in patients with FHC and retinal scars in the absence of toxoplasmosis.

Background: The Toxocara larva is known to migrate across the retina, but the layer in which it migrates and its effect on the retina has been unknown., Case: An ocular Toxocara infection was diagnosed by an immunological test on a vitreous sample from a patient with a retinal lesion that had migrated. Optical coherence tomography (OCT) and fluorescein angiography (FA) were used in this investigation., Observations: Many small lesions were first detected in the peripheral retina, and vitrectomy was performed because of vitreous haze. Two peripapillary lesions were found during the vitrectomy. OCT of one lesion demonstrated a highly reflective mass located in the nerve fiber layer, and FA showed dye leakage from the lesion as well as hyperfluorescence of the disc. Three weeks later, another lesion was found in the macular area, and OCT and FA findings were the same as for the first lesions. Fluorescein leakage was also observed along the presumed path of the migrating larva., Conclusions: The movement of the lesion from the peripapillary area to the macular area suggested that a Toxocara larva had migrated across the retina. OCT images indicated that the larva moved in the nerve fiber layer, and FA showed that it caused severe inflammation along its pathway.

Ocular toxocariasis named also ocular larva migrans is caused by larvae of the roundworm Toxocara spp. The purpose of this study was to find out the seroprevalence of Toxocara antibodies in patients suspected of ocular toxocariasis. Between January 2001 and December 2003, sera from 239 ocular patients, aged 3 to 80 years, were examined by ELISA and confirmed by Western blot test. Out of the 239 patients, 172 (72%) were seronegative and 67 (28%) were Toxocara seropositive; 95% CI (22-34%). The median age of Toxocara seropositive patients was 37.6 years. There was no significant difference in the number of Toxocara positive sera between the younger age group (< or = 14 years) and the older age group (> 14 years), p > 0.05. A high rate of Toxocara seropositivity in ocular patients should alert the ophthalmologists in Slovenia to include toxocariasis in the differential diagnosis of eye diseases more frequently.

Purpose: To describe the morphologic alterations in ultrasound biomicroscopy (UBM) present in peripheral vitreoretinal toxocariasis., Methods: An observational prospective study of case series. Fifteen eyes of 15 patients with clinical and laboratory diagnosis of peripheral vitreoretinal toxocariasis were enrolled. The patients were submitted to UBM examination of the region corresponding to the pars plana of the affected eye., Results: The most common morphologic alterations found by UBM in patients with peripheral vitreoretinal toxocariasis were as follows: vitreal membranes (13 cases), toxocara granuloma (11 cases), and pseudocysts (8 cases). Other less frequent findings were thickening of the ciliary body (6 cases), cystic formation (2 cases), peripheral retinal detachment (2 cases), rectification of the iris root (1 case), and posterior synechiae (1 case)., Conclusions: UBM allows detection of well-defined morphologic alterations associated with peripheral vitreoretinal toxocariasis, being useful to reinforce the clinical diagnosis.

The paper is presenting the selected problems regarding clinical pathology of ophthalmic toxocariasis, as well as methods of its diagnosis, especially immunodiagnosis. The outline of contemporary treatment of this entity is also presented. The data involves the description of Toxocara's life development cycle and data regarding epidemiology of this zoonosis as well.

Sera form 68 patients aged 1-30 years, suffering from posterior pole granuloma, peripheral granuloma, uveitis, endophthalmitis, optic neuritis and with a clinical diagnosis of suspected ocular toxocariasis, were tested for the presence of anti-Toxocara antibodies. Antibodies to Toxocara were detected in 11 (17 per cent) subjects less than 15 years old and three (4 per cent) subjects more than 15 years of age using enzyme-linked immunosorbent assay. None of the controls sera (other helminthic diseases) were positive for anti-Toxocara antibody.

Ocular toxocariasis is a clearly defined disease. However, much remains to be learned concerning the migratory route, ocular changes, diagnosis and treatment. Studies in paratenic hosts have contributed to our understanding and will yield more information. Various experimental animals have been used, such as mice, rabbits, guinea pigs, primates, hamsters and gerbils. Of these, the last appear to be the most appropriate model due to their high susceptibility to ocular infection. Results obtained from different animal models are often not comparable due to the fact that dose and routes of inoculation are diverse. Early stages in the pathogenesis of ocular toxocariasis are manifested by haemorrhages in the anterior chamber and iris, replaced in time by accumulations of white cells. Ocular migration produces an early cell reaction, formed by an infiltration of neutrophils accompanied by vasculitis and retinal microinfarcts. Over a period of time, an increase of macrophages and the distribution of the infiltrates is observed. Later, granulomatous lesions are formed. These do not necessarily contain a larva and their appearance varies in different animal models. Local production of IgE and the presence of specific IgG have been described.

Toxocara canis is a nematode that may be involved in human ocular toxocariasis. Specific immunotesting is of importance but may be negative as toxocara antigens may localize exclusively in vitreous humor. We report here the case of one patient with optic disc toxocariasis granuloma negative for toxocara canis immunodiagnostic on serum. Clinical diagnosis was confirmed by toxocara canis specific enzyme-linked immunosorbent assay (ELISA) on aqueous humor showing elevated titers of antibodies. Systemic steroids associated to specific treatment of toxocariasis were initiated. Follow-up displayed regression of uveitis but development of vitreous bands leading to posterior retinal detachment. Toxocara posterior granuloma is of poor visual prognosis. Moreover, diagnosis may be of late setting, as clinical features are often unrecognized and specific immunodiagnostic on serum negative. Specific immunotesting on aqueous humor is of particular importance to rule out severe clinical differential diagnosis such as retinoblastoma in children. Ultrasound biomicroscopy (UBM) seems to be specific and sensitive in patients with a presumed diagnosis of peripheral toxocariasis. Granuloma surgery appears to yield good clinical results and allows histological confirmation of the diagnosis.

Purpose/methods: A 14-year-old girl with a history of contact with puppies and chronic bilateral panuveitis was examined. The fundus of the right eye showed an inferotemporal pars plana exudate. The fundus of the left eye showed an elevated posterior mass., Results/conclusion: Toxocara antibodies in the aqueous humor detected by enzyme-linked immunosorbent assay had a Goldmann-Witmer coefficient of 8.63 in the right eye and 8.94 in the left eye. Toxocariasis may be a cause of bilateral panuveitis.

In La Réunion island (Indian Ocean) a seroepidemiological survey for toxocariasis was carried out among 387 subjects over 15 years old by Western blotting using Toxocara canis excretory-secretory larval antigens; 92.8% of the sera were positive. Statistical study, including logistic regression analysis, showed a significant correlation of Western blot results with sex, age, and absence of water supply. The final logistic model demonstrated that only the last 2 factors were significant multiplicative risk factors for toxocariasis. Sex was an independent risk factor. With this level of infection, we suggest that further surveys of ocular toxocariasis in children and teenagers of La Réunion would be advisable.

The incidence of Toxocara antibodies was determined in 319 sera from patients suspected of having Toxocara infection. Serological responses were compared with clinical manifestations and age of the patients. A seropositive reaction was found in 24% of the patients. Highly positive results (OD 0.510-1.000 and OD > 1.000) by ELISA were obtained significantly more frequently in younger patients than in older ones (p < 0.005). The percentage of seropositive patients with visceral disorder was found to decrease with age, whereas the proportion of seropositive patients with ocular disorder increased with age. Serologically confirmed Toxocara infection in Slovenia alerted us to the fact that this health issue should be given due attention in the future.

The number of infections with larvae of the Toxocara canis worm has been continuously increasing in the Polish population, and the diagnosis and treatment of this disease is difficult. The authors describe 81 cases of eye infection in children and youth at the age of 3 to 18 years. The lesions in 94 eyes were observed for 0.5 to 11 years. In all patients the diagnosis was confirmed by ELISA test. In the clinical picture various forms of uveitis and granuloma of the eye fundus were found. The treatment consisted in general and topical application of antihelmintics, antibiotics and corticosteroids. In 23 eyes photocoagulation, in 11 cryopexy, and in 3 vitrectomy was performed. Clinical improvement was observed in 50 eyes, stabilization of the lesions in 41 eyes, and deterioration in the remaining 3 eyes. The authors conclude that the best results are obtained through conservative treatment combined with photocoagulation and cryopexy.

Ocular toxocariasis is rare and therefore the spectrum of clinical disease is difficult to establish. We present a review of the clinical features and laboratory findings in a group of patients with positive Toxocara serology and ocular toxocariasis. The clinical spectrum was diverse and milder disease was commoner than might be supposed from reviews of the literature. Eosinophilia was unusual, but featured in two cases of unilateral pars planitis.