Ocular cysticercosis

What it is

Humans ingest tapeworm eggs through contaminated food, water or hands. Larvae can travel to the brain, muscles or eye. In the eye they may sit in the vitreous gel or under the retina, triggering inflammation that damages vision.

Symptoms in the eye

Symptoms depend on where the cyst sits and whether inflammation flares.

• New floaters or a moving shadow in vision
• Blurred or decreased vision, often one eye
• Red, painful eye if inflammation is active
• Rarely, a visible white cyst on examination

Where it occurs

Ocular cysticercosis is reported most often in rural Latin America — including Mexico, Peru and Ecuador — and in other Taenia solium endemic settings. Short-term travellers are at low risk; long-term residents in endemic villages face higher exposure if pork and hygiene practices are unsafe.

Diagnosis and treatment

Specialist eye examination and imaging (including ultrasound of the eye) can show cysts. Treatment may involve anti-parasitic medicines and sometimes surgery to remove a cyst, coordinated with neurology if the brain is involved. Early specialist care improves outcomes.