Orbital Myocysticercosis

Myocysticercosis is a cyst of the pork tapeworm larva (Taenia solium) inside a muscle that moves the eye. It is common in India.

• It is caught by swallowing tapeworm eggs in contaminated food or water, or from hands that have not been washed after using the toilet.
• It often affects children and young adults.
• Symptoms include swelling of the eyelid, a drooping eyelid, a bulging eye, difficulty moving the eye, double vision, and recurring pain and redness.

Rarely, the cyst presses on the nerve of the eye and affects vision. Any drop in vision needs urgent assessment.

• An ultrasound of the orbit usually shows the cyst, often with a bright spot (the head of the larva). A CT or MRI scan confirms it.
• A brain scan is advised before treatment, to check for cysts in the brain (neurocysticercosis).

• Most patients are treated with tablets: an anti-parasite medicine (albendazole) together with steroids, which control the inflammation caused as the cyst dies.
• Surgery is needed less often, for example for a cyst just under the surface of the eye or eyelid, a cyst that comes back, or pressure on the nerve of the eye.
• Ultrasound is repeated during follow-up to confirm that the cyst has gone. This usually takes several weeks to a few months.
• Some patients are left with limited eye movement or a drooping eyelid.

• Wash hands after using the toilet and before eating.
• Wash fruit and vegetables well, and avoid undercooked pork.