Author: Marta Bautista Salamanca (Spain)
Co-authors: Marta Maria Medina Baena, Olga Cejudo Corbalan, Ana Maria Delgado Romero
Purpose
Toxocariasis is a parasitic disease caused by dog and cat roundworms, Toxocara canis and Toxocara cati, respectively. Humans can be infected by contact with infected environments or through consumption of underwashed fruits and vegetables. Ocular toxocariasis often presents as unilateral loss of vision or floaters, and it is more frequently seen in older children and adolescents. There are three forms of clinical presentation: posterior pole granuloma (as whitish or yellowish mass), peripheral retinal granuloma and panuveitis. The diagnosis is usually made by the identification of the typical ophthalmologic features and epidemiologic exposure, since serum antibodies to Toxocara may often be undetectable. Treatment is directed at reducing damage to the eye through reduction of ocular inflammation with corticosteroids. The use of anthelmintic drugs (albendazol) combined with corticosteroids has shown favorable outcomes in some studies.
Setting/Venue
We present 2 cases of this type of uncommon retinal lesion in our area, one case in an adult and the other one in a child, as well as the follow-up and treatment for each case.
Methods
Case 1. 53-year-old male with loss of vision in his right eye (OD) from a week now. No pets. Best corrected visual acuity (BCVA) in his OD “hand motion” and in his left eye (OS) 1. Fundus examination OD reveals foveal fibrous mass, OS normal. No other examination findings. Macular OCT OD: subretinal round mass with subretinal and intraretinal fluid. Fluorescence angiography: inflammatory mass with hyper fluorescence. Positive serum antibodies to Toxocara and positive Mantoux test. Case 2. 7-year-old female who refers low visual acuity. She lives with dogs. BCVA in her OD 0.2 and in her OS 1. Fundus examination OD reveals whitish mass temporal to the optic disc, OS normal. No other examination findings. Macular OCT: peripapillary mass which resembles a fibrous granuloma by Toxocara. Fluorescence angiography: inflammatory peripapillary mass with no intrinsic vascularity. Negative serum antibodies to Toxocara.
Results
Case 1 was treated with albendazol and complete treatment for tuberculosis with isoniazid, rifampicin, pyrazinamide and ethambutol. When tuberculosis treatment was finished, corticosteroids were added. The patient BCVA and his lesion are stable until the present day, having past 9 months. In Case 2, having excluded sings of inflammation or malignancy, treatment was focused on her amblyopia, prescribing full optical correction and occlusion on her OS. One month later she reached BCVA 0.6 and at present, 5 months later, her BCVA is 0.9 and the lesion remains stable.
Conlusions
When facing a retinal lesion, especially if it has granulomatous characteristics, it is imperative to make a good anamnesis with epidemiologic exposure to animals in order to reach the diagnosis of an ocular toxocariasis. Furthermore, since this pathology is more frequent in children, treatment of the amblyopia must not be forgotten, being able to have as a result a considerable improvement of the patient visual acuity.
Financial Disclosure
None.
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