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69-Year-Old Female with Fall on Blood Thinners
This case features a 69-year-old female on blood thinners presenting after a fall, ultimately diagnosed with retrolaminar silicone oil migration.
Imaging overview:
Axial non-contrast CT demonstrates hyperdense material along the optic nerve sheath on the right. Additional axial and coronal non-contrast CT images show hyperdense material tracking along the optic chiasm and tract, as well as non-dependent layering within the ventricles consistent with silicone oil floating in CSF. The distribution and non-dependent behavior of the hyperdense material is characteristic of retrolaminar silicone oil migration rather than hemorrhage.
Clinical insight:
Retrolaminar silicone oil migration is a rare complication of intraocular silicone oil tamponade, used in the repair of complex retinal detachments. Silicone oil can migrate through the optic nerve sheath into the subarachnoid space and track along the visual pathway, including the optic nerve, chiasm, and optic tracts, eventually reaching the ventricles where it floats non-dependently due to its low density relative to CSF. On CT, the migrated silicone oil appears hyperdense and can closely mimic hemorrhage, making awareness of prior intraocular silicone injection essential for correct interpretation. Familiarity with the characteristic distribution along the visual pathway and non-dependent intraventricular floating pattern is key to avoiding misdiagnosis, particularly in the trauma setting.
Case courtesy of Kelly Dahlstrom, DO, University of Kansas Health System.