Pars plana vitrectomy and subretinal surgery for ocular toxocariasis

Ocular Toxocariasis: Beyond Typical Patterns through the New Imaging Technologies

PURPOSE

To report five cases of ocular Toxocariasis (OT) in which ultrawide-field (UWF) imaging was helpful in diagnosis and assessment. OT is an underdiagnosed condition triggered by the ocular invasion of Toxocara larvae. Typical features are peripheral granuloma or endophthalmitis.Methods: A retrospective case series of 10 outpatients were studied by complete ophthalmologic examination and complementary tests. UWF retinal imaging, fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SDOCT) were retrospectively analyzed. Five patients with suspected OT were included.Results: UWF imaging and FAF was able to detect all retinal lesions in a single rapid capture. Two patients showed positive serology for Toxocara. An image suggesting the larva in the vitreous cavity was shown in one patient. Antihelmintic 15 treatment along with steroids was prescribed in two patients.Conclusion: UWF imaging and SDOCT provide a more efficient approach and follow-up in OT, raising final standards of care.

Ocular Toxocariasis: Clinical Features and Long-term Visual Outcomes in Adult Patients

PURPOSE

To investigate clinical characteristics and treatment outcomes of proven ocular toxocariasis (OT) in adult patients.

DESIGN

Retrospective, consecutive, interventional case series.

METHODS

setting: Institutional.

STUDY POPULATION

Consecutive OT patients with positive serum serology and positive western blot (WB) on ocular sample.

OBSERVATION PROCEDURES

Clinical features, optical coherence tomography (OCT), and treatment outcomes.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA) and OCT central foveal thickness (CFT).

RESULTS

Fourteen patients were included between 2011 and 2013. Mean age at diagnosis was 45.6 years. Mean duration between the first symptoms and diagnosis was 15.1 months. Uveitis was unilateral in all cases and all patients displayed vitreous inflammation. The main baseline findings were presence of ≥1 peripheral granulomas (57.1%), vasculitis (57.1%), vitreoretinal traction (57.1%), and chronic macular edema (ME) (71.4%). Delayed diagnosis (>8 months) seemed to be associated with higher rate of ME. All patients received albendazole. Systemic (n = 5) and/or local corticosteroids (CS) (n = 7) were administered in case of ME and/or posterior segment inflammation. Vitrectomy was performed when vitreous inflammation was severe and persistent despite CS or in case of threatening traction or visually significant epimacular membrane (28.6%). Overall, this regimen allowed significant decrease of CFT (P = .01). In the vitrectomy subgroup, mean BCVA increased (P = .01) and CFT decreased (P = .017).

CONCLUSION

While some features such as granuloma are typical signs of OT, atypical features can delay the diagnosis. In doubtful situations, WB on ocular samples seems to be more specific than serum antibodies alone. ME seems to be a common complication of longstanding OT in the adult.

A case of ocular toxocariasis successfully treated with albendazole and triamcinolon

We present a case of ocular toxocariasis treated successfully with oral albendazole in combination with steroids. A 26-year-old male visited the authors' clinic with the chief complaint of flying flies in his right eye. The fundus photograph showed a whitish epiretinal scar, and the fluorescein angiography revealed a hypofluorescein lesion of the scar and late leakage at the margin. An elevated retinal surface and posterior acoustic shadowing of the scar were observed in the optical coherence tomography, and Toxocara IgG was positive. The patient was diagnosed with toxocariasis, and the condition was treated with albendazole (400 mg twice a day) for a month and oral triamcinolone (16 mg for 2 weeks, once a day, and then 8 mg for 1 week, once a day) from day 13 of the albendazole treatment. The lesions decreased after the treatment. Based on this study, oral albendazole combined with steroids can be a simple and effective regimen for treating ocular toxocariasis.

Multifocal granulomata in presumed Toxocara canis infection in adult

Human infection of Toxocara canis in eye is usually an outcome of accidental ingestion of the embryonated eggs. The average age at diagnosis of ocular Toxocariasis is 7.5 years, ranging from 2 to 31 years. It constitutes 1%-2% of uveitis in children. Diagnosis is based upon the clinical features observed in a young patient and confirmed by the presence of specific IgG in the serum or aqueous humor by Enzyme-linked immunosorbent assay test. We report a case of Presumed Toxocara infection in 45-year-old male which is unique in presentation with multifocal granulomata in retina. Our PubMed search could not produce case with similar presentation. Probably this is the first reported case of multifocal granulomata in presumed ocular Toxocara in any age group

Ocular toxocariasis

Ocular toxocariasis is an uncommon worldwide parasitic infection that affects mostly children and is found in both rural and metropolitan areas. In many parts of the world, parasitic infections of the eye are a major cause of blindness. The diagnosis of toxocariasis is essentially clinical, based on the lesion morphology and supportive laboratory data such as serum enzyme-linked immunosorbent assay (ELISA) titers and ELISA Toxocara titers on aqueous humor; other diagnostic methods are imaging studies including optical coherence tomography, fluorescein angiography, computed tomography, and ocular ultrasound. Treatment is directed at complications arising from intraocular inflammation and vitreous membrane traction. Early vitrectomy may be of value both diagnostically and therapeutically.

Surgical Treatment of Ocular Toxocariasis: Anatomic and Functional Results in 45 Patients

Purpose

TO evaluate the anatomic and functional outcome after surgery in patients with complicated ocular toxocariasis.

Methods

A retrospective review of the medical records of pediatric patients who underwent a surgical procedure for ocular toxocariasis from July 1990 to January 2005. Patients with postoperative follow-up shorter than 6 months were excluded from the study. Best-corrected visual acuity (BCVA) was arbitrarily divided into 5 groups: 1) no light perception (NLP); 2) light perception (LP) and hand motion (HM); 3) finger counting (FC) to 20/400; 4) 20/300 to 20/60; and 5) 20/50 to 20/20.

Results

Forty-five patients with a mean age of 8.1 years (range 6–10) were included in the study. The ocular toxocariasis presentation most commonly encountered was peripheral granuloma (38%). Twenty-one eyes presented with BCVA in the LP/HM group, 18 (40%) eyes in the FC to 20/400 group, 5 (12%) eyes in the 20/300 to 20/60 group, and 1 (5%) eye in the 20/50 to 20/20 group. The most common surgical procedure was pars plana vitrectomy (PPV) in 58% of the eyes. Four eyes (9%) presented with postoperative BCVA of NLP, 2 eyes (4%) in the LP/HM group, 12 eyes (27%) in the FC to 20/400 group, 19 eyes (42%) in the 20/300 to 20/60 group, and 8 eyes (18%) in the 20/50 to 20/20 group.

Conclusions

Surgical treatment of severe ocular complications secondary to toxocara infections results in satisfactory anatomic results and may improve the overall visual outcome of these patients.

Treatment of ocular toxocariasis with albendezole: a case report

BACKGROUND

Toxocara canis is a parasite that can infect the eye and create a significant inflammatory response that can be detrimental to the patient's vision. Its clinical presentation can mimic other causes of uveitis, and its diagnosis and treatment can be challenging. Prompt and accurate diagnosis of ocular toxocariasis is essential to prevent permanent visual loss.

CASE REPORT

A 7-year-old Hispanic boy presented to the clinic with complaints of reduced visual acuity in the left eye. After a careful evaluation of his ocular health, he had ocular toxocariasis diagnosed and confirmed by enzyme-linked immunosorbent assay testing. Treatment with the anthelmintic, albendazole, and oral steroids was initiated. There was initial improvement of the vitritis with significant vitreous debris. However, 2 years later, reactivation occurred, and a vitrectomy was required. This case report reviews the management of a patient with active ocular toxocariasis, including clinical findings and treatment options.

CONCLUSIONS

The differential diagnosis of ocular toxocariasis and review of the available treatments are presented.

A review of pediatric uveitis: Part I. Infectious causes and the masquerade syndromes

Uveitis is a manifestation of complex processes that can represent an infectious or a purely immune system modulated condition and may have grave effects on the eye. Much of the morbidity in these conditions is the result of the immune response to these stimuli. These infectious diseases may be successfully treated by addressing the inciting organism with recognized interventions. Treatment of the immune response to the organism often must be pursued simultaneously to minimize long-term complications caused by structural changes within the eye. Assisting the individual's immune response to eliminate the organism while minimizing the immune response's damaging effects remains a unique challenge drawing on both the science and the art of medicine. Several non-infectious conditions that are not autoimmune diseases may commonly masquerade as uveitis, leading to delays in appropriate treatment.

Pars plana vitrectomy revealed Toxocara canis organism

BACKGROUND

The Toxocara organism may cause direct injury to the eye, but most commonly, host inflammatory reactions are responsible for the resulting compromise. The inflammatory response created by the ocular involvement may result in epiretinal membrane formation, tractional or combined tractional-rhegmatogenous retinal detachment. The treatment of choice is pars plana vitrectomy (PPV), which also has diagnostic significance.

METHODS

We report a pediatric case in which PPV recovered the Toxocara canis organism. For the total tractional retinal detachment diagnosed after the cataract surgery, PPV, preretinal and subretinal membrane peeling, 180 degrees retinotomy, silicone oil injection were performed. The fibrous membrane specimen obtained during PPV recovered the Toxocara canis organism.

RESULTS

The intense postoperative inflammatory reaction had to be managed surgically, also. Retinal reattachment was achieved with subsequent improvement of the visual acuity.

CONCLUSION

The importance of vitreous biopsy examination following PPV, in eyes in which etiology is uncertain and the intense antiinflammatory therapy applied within and following vitreoretinal surgery is emphasized.

[Ocular toxocariasis. From biology to therapy]

Ocular toxocariasis represents an organ manifestation of the systemic infection with the Nematode larva Toxocara canis. The infection can provoke very different changes in the eye. Especially posterior uveitis, vitreous body infiltrates, epiretinal membranes and suberetinal granulomas can occur. The diagnosis of these changes can be difficult due to the variety of the symptoms and on the other side by the absence of characteristic specific changes. Moreover unclear findings can occur when only serological examinations are performed. In unclear cases the antibody-detection by means of ELISA from the vitreous body fluid can be useful. The examination of vitreous body material can prove toxocara infection when no systemic signs of infection are present and no antibodies are detectable in the serum. Besides the systemic anti-helminthic therapy with Albendazol the pars plana vitrectomy is a substantial therapeutic option in ocular toxocariasis when vitreo-retinal complications are present. A well timed adequate therapy can stabilize the visual acuity in many cases.

The effect of an indirect anthelmintic treatment on parasites and breeding success of free-living pheasantsPhasianus colchicus

In Great Britain free-living common pheasantsPhasianus colchicusare often managed at high densities owing to their popularity as a quarry species. They are prone to infection by a range of parasite species includingHeterakis gallinarum,Capillariaspp. andSyngamus trachea. In 1995 the efficacy of an indirect anthelmintic technique for controlling parasitic worm burdens of pheasants was determined in a pilot study on a shooting estate in the south of England. Between 2000 and 2003 a large-scale field experiment was conducted on nine estates in eastern England to determine the effect of the technique on parasite burden and pheasant breeding success. In the absence of anthelmintic treatment worm burdens increased rapidly through March and April, whereas birds given anthelmintic-treated grain had lower worm burdens during the same period. The breeding success of pheasants was significantly higher on plots provided with anthelmintic treatment, although no long-term increases in population densities were observed. The burdens of the most common parasiteH. gallinarumwere significantly lower in pheasants from treatment plots six weeks after the anthelmintic treatment had ceased, but spring treatment did not influence parasite burden in the following winter.

Eosinophil cationic protein, specific IgE and IgG4 in human toxocariasis

Among 67 French patients presenting a toxocaral infection, various demographic, environmental, clinical and laboratory parameters (blood eosinophil count, eosinophil cationic protein (ECP), serum total IgE, specific IgE against common inhalant allergens, specific IgE and IgG4 againstToxocaraexcretory-secretory antigens) were investigated. Correlation studies and logistic regression analyses were conducted, testing elevated levels of ECP, specific anti-ToxocaraIgE or IgG4 as outcome variables An elevated ECP level was significantly associated with both cough and rhinitis, a high level of specific anti-ToxocaraIgE with itchy rashes and possible atopic status, and an increase of specific anti-ToxocaraIgG4 with rural residence.

[Ocular toxocariasis. Diagnostic and therapeutic options]

BACKGROUND

The diagnosis of ocular toxocariasis can be difficult and the aim of this study was to evaluate the benefit of ELISA testing of vitreous body fluid.

PATIENTS AND METHODS

We present five consecutively treated patients with ocular symptoms of toxocariasis, three of these patients presenting with epiretinal membranes and subretinal granulomas were vitrectomized. Vitreous and body fluid and serum were tested for toxocara antibodies by ELISA. Moreover vitreous body fluid of 10 patients with epiretinal membranes of other origins were examined by the same ELISA.

RESULTS

In all three operated patients toxocara antibodies were detected in the vitreous fluid but ELISA testing of serum samples was negative in two of the three patients. Visual acuity increased or remained stable in the operated patients. The ELISA test was negative in all vitreous fluid samples of the control group.

CONCLUSIONS

ELISA testing of vitreous body fluid can prove the presence of toxocara infection when no systemic signs of infection are present and no antibodies are detectable in the serum. Well-timed vitrectomy is a suitable therapy for vitreo-retinal complications in ocular toxocariasis to improve prognosis and to confirm the diagnosis.

Nematode infections of the eye: toxocariasis and diffuse unilateral subacute neuroretinitis

In many parts of the world, parasitic infections of the eye are a major cause of blindness. The parasites Toxocara canis, Onchocerca volvulus, Taenia solium, Ancylostoma caninum, and Cysticercus celulosae all have been responsible for blinding ocular infections. The nematodes T. canis and Toxocara cati are parasitic roundworms that infect dogs (toxocarosis), other canidae, and cats. Ocular toxocariasis is an uncommon worldwide infection caused by the nematode larvae of T. canis, commonly found in dogs. Human transmission is usually via geophagia, the ingestion of food contaminated with Toxocara eggs, or contact with infected puppies, often resulting in devastating ocular or systemic effects. Ocular toxocariasis is typically a monocular disease of young children, and its clinical findings include posterior and peripheral retinochoroiditis, optic papillitis, and endophthalmitis. The inflammatory response created by ocular involvement may result in epiretinal membrane formation, traction retinal detachment, and combined traction-rhegmatogenous retinal detachment. Diffuse unilateral subacute neuroretinitis is another ocular parasitic infection that usually results in severe visual loss. Evidence suggests that diffuse unilateral subacute neuroretinitis is caused by a solitary unidentified nematode of two different sizes, but to date, only a small number of nematodes have been recovered from eyes affected with the infection. Diffuse unilateral subacute neuroretinitis occasionally can affect the fellow eye.

Treatment of ocular toxocariasis with albendazole

The purpose of this study was to evaluate the efficacy of combined albendazole and steroid treatment for uveitis caused by Toxocara canis in immunocompetent patients. Five patients (7 eyes) with ocular larva migrans syndrome (OLM) were used in this study. Toxocariasis was suspected based on clinical manifestations and confirmed by anti-toxocara IgG and Western blot analysis. Systemic albendazole (adults: 800 mg b.i.d.; children: 400 mg b.i.d.) was given in conjunction with steroids. Visual acuity before and after therapy, inflammatory response, side effects and toxicity were evaluated. Treatment resulted in an improved visual acuity in all patients. Mean initial Snellen visual acuity was 20/40, and mean final acuity was 20/20. There were no recurrences of uveitis throughout the observation period (average: 13.8 months; range: 3 days to 24 months). These findings suggest that albendazole, in combination with systemic steroids, is a useful regimen to treat ocular larva migrans syndrome.

Highlights of human toxocariasis

Human toxocariasis is a helminthozoonosis due to the migration of Toxocara species larvae through human organism. Humans become infected by ingesting either embryonated eggs from soil (geophagia, pica), dirty hands or raw vegetables, or larvae from undercooked giblets. The diagnosis relies upon sensitive immunological methods (ELISA or western-blot) which use Toxocara excretory-secretory antigens. Seroprevalence is high in developed countries, especially in rural areas, and also in some tropical islands. The clinical spectrum of the disease comprises four syndromes, namely visceral larva migrans, ocular larva migrans, and the more recently recognized "common" (in adults) and "covert" (in children) pictures. Therapy of ocular toxocariasis is primarily based upon corticosteroids use, when visceral larva migrans and few cases of common or covert toxocariasis can be treated by anthelmintics whose the most efficient appeared to be diethylcarbamazine. When diagnosed, all of these syndromes require thorough prevention of recontamination (especially by deworming pets) and sanitary education.

Five cases of ocular toxocariasis confirmed by serology

We report 5 cases of ocular toxocariasis in Korean adults complaining of visual impairment along with floating or bubbling sensation. Fundoscopic examination revealed a retinal detachment along with exudate in 4 cases. They all showed typical reaction by ELISA and immunoblot against Toxocra excretory-secretory antigen. One case showed high level of anti-Toxocara IgE antibodies (34,000 Toxocara units/L) as well as increased level of serum total IgE antibodies and the specific IgE antibodies for 3 inhalant antigens, suggesting that high level of anti-Toxocara IgE antibodies was associated with an atopic status. Clinical manifestations were improved after the sequential use of steroids then mebendazole. We also suggest that ocular toxocariasis should be thoroughly investigated even when an evocative uniocular inflammatory lesion is encountered in peripheral retina without a systematic disease.

The role of submacular surgery in the treatment of choroidal neovascular membranes

The growth of choroidal neovascular membranes (CNVM) beneath the macula can cause significant disturbances of central vision. Conditions such as age-related macular degeneration (AMD) and presumed ocular histoplasmosis syndrome (POHS) are the most common etiologies. The Macular Photocoagulation Study group presented data that clearly showed laser photocoagulation to be beneficial in the treatment of CNVM. Poor visual results and a high rate of recurrence have prompted clinicians to seek out alternative treatments. Experiences with CNVM removal utilizing submacular surgical techniques have shown that central visual function may be restored or preserved in POHS, multifocal choroiditis and idiopathic causes. The Submacular Surgery Trials were designed to investigate whether submacular surgery is more effective in retaining central acuity in patients with subfoveal CNVM, than observation alone. The goal of this paper is to review the role of submacular surgery in the treatment of subfoveal choroidal neovascular membranes.

Ocular manifestations of systemic infections

Ocular involvement, mainly uveitis or retinochoroiditis, is common in various systemic diseases, such as endogenous endophthalmitis, Lyme disease, human T-cell lymphotropic virus type I infection, toxoplasmosis, and toxocariasis. Recent progress, especially in laboratory microbiologic testing, has enabled us to reliably diagnose many formerly idiopathic intraocular inflammatory diseases. A group of systemic infectious diseases, including those discussed here, are implicated as a body of emerging or re-emerging diseases that have appeared in the past two decades and are thought to have a close relation with global socioenvironmental changes. This paper discusses recent clinical and experimental studies of the most important systemic infectious diseases that affect the eye.