Toxocara Optic Neuropathy: About 02 Cases

Case Report

Austin J Clin Ophthalmol. 2023; 10(7): 1166.

Toxocara Optic Neuropathy: About 02 Cases

Hasnaoui Ihssan*; Amine Krichen; Salma Hassina; Bardi Chaimaa; Louai Serghini; Abdellah Elhassan

Department of Ophtalmologie B & Faculty of Medicine and Pharmacy, Hospital of Specialities, University Mohamed V, CHU ibn Sina Rabat, Morocco

*Corresponding author: Hasnaoui I Department of Ophtalmology B, Faculty of Medicine and Pharmacy, University Mohamed V, Av. Abderrahim Bouabid, 10100 Rabat, Morocco. Email: ihssanhasnaoui@gmail.com

Received: September 07, 2023 Accepted: October 14, 2023 Published: October 21, 2023

Abstract

Ocular toxocariasis is recognized to be a cause of childhood blindness. It usually results as a sequel of systemic infestation with the second or third stage larva of T. cani (visceral larval migrans). It is an uncommon cause of uveitis that mainly affects younger patients. Inflammation is typically unilateral and presents as either a granuloma in the peripheral or posterior retina or a moderate to severe vitreous inflammation mimicking endophthalmitis. We report two cases of children with ocular toxocariasis with posterior granuloma, negative for specific serodiagnosis. An anterior chamber puncture of the anterior chamber and an ELISA test with homologous antigens of Toxocara canis on the acqueous humor made the diagnosis diagnosis.

Keywords: Optic neuropathy; Toxocariasis; Ocular toxocariasis; Toxocara optic neuropathy

Introduction

In many parts of the world, parasitic infections of the eye are a major cause of blindness [1].

Ocular Toxocariasis (OT) is an uncommon disease that occurs primarily in young patients. It affects females and males with approximately equal frequency. Toxocariasis or visceral larva migrans is a cosmopolitan parasitic zoonosis caused by Toxocara canis or Toxocara cati or, even more rarely, by nematode larvae from wild animals. The prevalence rate in industrialized countries is 2-5% in urban areas, 37% in rural areas. Major forms include visceral larva migrans syndrome, neurological toxocariasis and ocular toxocariasis. Ocular involvement is rare, and manifests itself essentially in three forms: pan-uveitis, posterior granuloma and peripheral granuloma.

Patients and Observation

Case 1

A 10-year-old child with no medical history was admitted for a sudden vision loss of the right eye. On ophthalmological examination, the visual acuity was reduced to hand motion in the right eye, the anterior segment was calm; the fundus showed intermediate uveitis and a parapapillary granuloma surrounded by retinal elevation (Figure A); the ophthalmological examination of the left eye did not reveal any abnormality. Ocular ultrasound revealed a small, heterogeneous echogenic formation forming a voluminous papillary protrusion with no visible calcification (Figure B). Biological tests revealed a hypereosinophilia of 920/mm3, a normal chest X-ray and a negative tuberculin skin test. Blood serologies were negative for both toxoplasmosis and toxocariasis (Toxocara canis ELISA technique). On the aqueoushumor, the PCR test for toxoplasmosis DNA was negative, and the ELISA immunodiagnosis for toxocariasis was positive at 1.725. Western blot also confirmed the diagnosis. Appropriate treatment was instituted, including general corticosteroid therapy (prednisone 1mg/kg/d) and minute antiparasitic treatment with albendazole. At the end of the treatment, the uveitis disappeared without any improvement in visual acuity.