Protozoal infections of the cornea and conjunctiva in dogs associated with chronic ocular surface disease and topical immunosuppression.

OBJECTIVE: To describe five cases of protozoal keratitis or conjunctivitis in dogs with chronic preexisting ocular surface disease treated with long-term immunosuppression. ANIMALS STUDIED: Five dogs that developed corneal or conjunctival mass lesions. PROCEDURES: The database of the Comparative Ocular Pathology Laboratory of Wisconsin was searched for canine cases diagnosed with corneal or conjunctival protozoal infection. Five cases were identified, and tissues were examined using routine and special histochemical stains: immunohistochemical labels for Neospora caninum, Toxoplasma gondii, and Leishmania spp., and tissue sample PCR for Leishmania spp., Trypanosoma cruzi, tissue coccidia (i.e., T. gondii/Sarcocystis/Neospora), piroplasms, trichomonads, and Acanthamoeba. Electron microscopy was performed for two cases, and serology for N. caninum and T. gondii was available for three cases. RESULTS: Preexisting ocular diseases included keratoconjunctivitis sicca and pigmentary keratitis (n = 4) and pyogranulomatous meibomian adenitis (n = 1). All dogs were treated with tacrolimus or cyclosporine for at least 1.2 years. Dogs were presented with fleshy corneal or conjunctival masses that were clinically suspected to be neoplastic (n = 4) or immune mediated (n = 1). Histologic examination revealed granulomatous inflammation with intralesional protozoal organisms. Amoeba (n = 2), T. gondii (n = 2), or Leishmania mexicana (n = 1) were identified using molecular techniques. Serological tests were negative. CONCLUSIONS: Protozoal keratitis and conjunctivitis without systemic involvement appears rare and may be associated with chronic preexisting ocular surface disease treated with long-term immunosuppression. Based upon clinical appearance, lesions could be confused with neoplasia. This is the first report of amoebic keratoconjunctivitis in dogs and of L. mexicana in dogs in the United States.

ELISA-Confirmed Bilateral Ocular Toxocariasis with Different Features.

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.

Isolation of IgG antibodies to Toxocara in ankylosing spondylitis patients with acute anterior uveitis.

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.

A rare ocular complication after a heart transplant: toxoplasma retinitis.

Ocular infections after a heart transplant are rare; but when present, they generally appear during the first year after surgery. Ocular infections may cause significant loss of vision and morbidity if not diagnosed early. For that reason, heart transplant patients should undergo a routine visual examination during follow-up. We report our experience regarding the followup and treatment of a case of toxoplasma retinitis diagnosed in one of our heart transplant recipients.

A case report of ocular toxocariasis.

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.

What is the importance of Demodex folliculorum in Behçet's disease?

Demodex folliculorum is an obligate parasite and commonly detected in patients with immune system deprivation. This study is planned to document the Demodex folliculorum prevalence among patients with Behçet's disease (BD). The patients who referred to the ophthalmology clinic were included in the study. Fourty patients with BD and 131 patients with refractive errors without any ocular and systemic disease were included. For parasite detection, 3 eyelashes from each inferior eyelid were epilated. Standardized skin surface biopsy (SSSB) was performed for detection of parasite at cheeks of patients. Samples were prepared with Hoyer's solution and investigated under the light microscope. There were 15 female and 25 male in BD group and 61 female and 70 male patients ine control group. Mean ages were 37.62 and 38.38 for BD and control groups, respectively. Demodex folliculorum prevalence at eyelashes was 65% for BD and 10% for control group. SSSB of cheek revealed 7.5% positivity for BD and 10% for control group patients. Statistical analysis documented a significant difference for eyelashes (p < 0.05) which could not be detected for skin results. Investigation of Demodex folliculorum in BD may be useful, even in patients without any complaint, for the treatment of ocular and eyelid discomforts of these patients.

Case of retinochoroiditis associated with porcine ascarids diagnosed by antibodies in subretinal fluid.

PURPOSE: To determine the cause of retinochorioditis in a patient with a granulomatous retinal exudate and an exudative retinal detachment. CASE: A 45-year-old man presented at another hospital with increased visual disturbances of the left eye. He was diagnosed with uveitis, and treated with topical steroids for 1 month. However, the uveitis worsened, and he was referred to our hospital. Ophthalmoscopy showed a yellowish-white granulomatous exudate, and an exudative retinal detachment in the lower peripheral retina. The retinal detachment worsened and affected the macula. Pars plana vitrectomy was performed, and the retina was reattached. During the surgery, ocular samples were collected for further examinations. The titers of antibodies against 12 kinds of ascaridis were examined, and elevated titers of specific antibodies against porcine ascarids were detected in the subretinal fluid, but not in the aqueous humor, vitreous, or serum. CONCLUSIONS: Vitrectomy with the collection of ocular samples, especially subretinal fluid, was a key procedure in the diagnosis and treatment of retinochoroiditis associated with the porcine ascarids.

Ultrasound biomicroscopy findings in peripheral vitreoretinal toxocariasis.

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.

Ocular toxocariasis in a North Indian population.

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.

Animal models in ocular toxocariasis.

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.

[Ocular toxocariasis. Value of local immunodiagnosis]. / Toxocarose oculaire. Intérêt de l'immunodiagnostic local.

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.

Subconjunctival infection with Dirofilaria repens: serological confirmation of cure following surgery.

Cases of zoonotic dirofilariasis infection, caused by Dirofilaria repens, occur widely throughout European, African, Middle Eastern, and Asian countries. The reports of this infection in humans in Spain are limited, and we herein report the case of a 43-year-old man from Elche (Alicante), Spain, who was seen with acute hyperemic reactivity of the temporal limbus of the right eye. A large nematode was visualized on examination and the intact worm was surgically removed. The parasite was identified as a mature but infertile female D repens. The level of serum antibodies against D repens was monitored for 6 months after surgery using immunoenzymatic assays. Serological results confirmed, as expected, the presence of a single worm and the parasitological cure after the surgical removal of the parasite. To our knowledge, this is the fourth autochthonous case of D repens infecting humans in Spain and also the first autochthonous case of subconjunctival localization.

[Particularities in the immune response in ocular cysticercosis]. / Particularités de la réponse immune dans la cysticercose oculaire.

In addition to the unique physiological and immunological features of the eye, previously presented, some parasitic factors of recent knowledge are induced during ocular cysticercosis. A modulation of the immune response of the host, mediated by larval products (a soluble RNA-peptide, some metacestode surface sphingoglycolipids) seems to occur in vivo. These recent findings lead us to make a critical review of the antigenic profiles obtained by Enzyme-linked immunoelectrotransfer blot assay (EITB) on samples collected from malagasy patients.

Pathologic features and immunofluorescent antibody demonstration of ocular microsporidiosis (Encephalitozoon hellem) in seven patients with acquired immunodeficiency syndrome.

We studied the clinicopathologic features of seven patients with acquired immunodeficiency syndrome (AIDS) and ocular microsporidiosis. All patients had decreased levels of CD4-positive cells (mean, 26/ml3) and ocular symptoms; five had bilateral punctate epithelial keratopathy, one had intermittent red eyes with conjunctivitis, and one had red eyes only. Light and electron microscopy of corneal and conjunctival biopsy and cytologic specimens and intact globes disclosed microsporidia belonging to the genus Encephalitozoon. Because E. cuniculi and E. hellem, the two species of the Encephalitozoon genus, are morphologically identical, an immunofluorescent antibody technique was used for species identification. In all seven patients, the agent was identified as E. hellem. Pathologic examination of globes obtained after autopsy disclosed E. hellem infection to be restricted to the corneal and conjunctival epithelium. We studied methods for the routine diagnosis of ocular microsporidiosis in patients with AIDS, including the role of immunofluorescent antibody staining.

Ocular toxocariasis in children and youth.

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.

Taenia crassiceps: experimental model of intraocular cysticercosis.

An experimental model of Taenia crassiceps intraocular cysticercosis was developed in rabbits. The objectives of this study were to analyze the pathophysiology of this parasitic infection and to evaluate the humoral immune response. Cysticerci, inoculated in the anterior chamber of the eye, were able to grow; no inflammatory changes in the eye or anticysticercus antibodies in serum or in aqueous humor were detected during the 12-day period. In contrast, rabbits that had previously been either infected intraperitoneally with living T. crassiceps cysts or immunized intramuscularly with T. crassiceps antigenic extract developed an intense inflammatory reaction in the eye and high levels of antibodies were detected in serum and aqueous humor even before the intraocular inoculation of parasites. Furthermore, intraocular cysticerci showed minimal growth and some were eliminated. These findings support the concept that the eye is an immunologically privileged site in the nonimmunized host and the importance of the immune response in the elimination of this parasitic infection.