QUIZ: No. 21, 27/07/2025

NCCT

MRI

ANS – Intracranial migration of intra-ocular silicone oil

Findings: High-density material at the anterior horns of both lateral ventricles. Additional linear hyperdensity is noted along the left optic nerve sheath, extending posteriorly from the left globe. The left globe also appears hyperdense, consistent with retained intraocular silicone oil.

Intracranial silicone oil migration is a rare complication resulting from silicone oil tamponade to treat retinal detachment. These hyperdensities are non-calcified, non-hemorrhagic, and located within non-dependent portions of the ventricles – characteristic for migrated intraocular silicone oil. Silicone oil accumulates in the non-dependent (anterior) horns of the lateral ventricles because it is less dense than CSF and therefore floats upward.

TEACHING POINTS

1.     Intraventricular silicone oil appears hyperdense on non-contrast CT, mimicking blood or calcification.

2.     Migration occurs through the optic nerve sheath, especially in eyes with optic disc pits, colobomas, or prior trauma.

3.     Management is conservative unless symptomatic or associated with ocular complications.