A 6-year-old boy with facial swelling and monocular blindness.

A 6-year-old boy presented to medical care in Tashkent, Uz-bekistan, with facial swelling. Clinical findings and radiological investigation suggested sinusitis, and the patient underwent a sinus drainage procedure. Following surgery, the patient was found to have proptosis, chemosis, dilated episcleral vessels, complete paralysis of all extra-ocular movements, no perception of light in the left eye, a dispersed hyphaema, and a ca-taractous lens. A presumptive diagnosis of traumatic posterior orbital arteriovenous fistula was made. Four days later, an undulating " stingray "-like organism was briefly seen in the left anterior chamber (figure 1). Further direct questioning revealed that the child frequently visited relatives in rural areas, where various domestic and farm animals lived. He was empirically treated with oral mebendezole. On the following day, the optic disc was noted to be markedly swollen on ultrasound examination, but there were no signs of the parasite within the globe. CT of the brain demonstrated a left frontal lesion, and ultrasound of the liver revealed 2 cystic lesions. What is your diagnosis?