[Ultrasonographic findings in ocular toxocariasis]

To evaluate ophthalmic ultrasound findings in the three presentation forms of ocular toxocariasis (peripheral or posterior pole granulomas and chronic endophthalmitis), in patients with confirmed diagnosis of ocular toxocariasis.

11 patients (11 eyes) with clinical and confirmed diagnosis of active ocular toxocariasis, presented positive ELISA test, were analyzed, prospectively, in the study. The patients were submitted to an ocular ultrasound examination (10-MHz transducer, contact technique).

In the series of 11 patients, mean age was 7.9 years-old (range from 2 to 17 y), 73% male, referring previous contact with dogs (91%), and with the soil (50%), no referral of appetite perversion. In the analyses of compromised eyes (11 eyes), the ophthalmoscopic examination revealed the following distribution of the 3 forms of ocular toxocariasis: 7 cases (63.6%), posterior pole granuloma; 1 (9.1%), chronic endophthalmitis; 2 (18.2%), peripheral granuloma; and 1 (9.1%), posterior pole granuloma associated with chronic endophthalmitis. Visual acuity impairment: no light perception (3 eyes, 27.3%); hand motion (4 eyes, 36.4%); counting fingers at 10 cm (1 eye, 9.1%); 20/200 (1 eye, 9.1%); 20/70 (1 eye, 9.1%); undefined (1 eye, 9.1%). Serology was positive to Toxocara canis (ELISA test) in 100% of the cases. Ophthalmoscopy was difficult or impossible in 64% of the cases due to the media opacity. Ultrasound findings noted were vitreous membranes with retinal attachment (100%); parietal lesions (granulomas) with high (80%) or medium (20%) reflectivity.

The most consistent ultrasound finding in the eye with toxocariasis was a high-reflectivity retinal mass, located in posterior pole or periphery, which may be calcified, and which has as main characteristic the adherence of vitreous membranes. In addition to clinical history, systemic evaluation and serology, the ultrasound can help in the diagnosis of ocular toxocariasis, especially in media opacities.