|LETTER TO THE EDITOR
|Year : 2022 | Volume
| Issue : 2 | Page : 68-69
A rare CT brain with intraocular hyperdensity
Neena Baby, Minu George, Suresh Kumar Radhakrishnan
Department of Neurology, Renai Medicity Multi Super-speciality Hospital, Kochi, Kerala, India
|Date of Submission||19-Jan-2022|
|Date of Acceptance||06-Apr-2022|
|Date of Web Publication||30-Jun-2022|
Department of Neurology, Renai Medicity Multi Super-speciality Hospital, Kochi, Kerala
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Baby N, George M, Radhakrishnan SK. A rare CT brain with intraocular hyperdensity. Amrita J Med 2022;18:68-9
Intraocular silicone oil has been used as a vitreous replacement and for the repair of retinal detachment. The knowledge of the radiological appearance of intraocular silicone is important as it can be mistaken for hemorrhage especially when there is a history of trauma.
| Clinical Description|| |
A 71-year-old man, known diabetic for 23 years, with diabetic retinopathy, nephropathy on hemodialysis was admitted with traumatic fracture neck of femur for which open reduction and internal fixation (ORIF) was done. He had a history of ischemic stroke, 10 years back, fully recovered, and had discontinued antiplatelet medications. He was on low-molecular-weight heparin for deep vein thrombosis (DVT) prophylaxis. On the fourth postoperative day, he became drowsy. On evaluation, he had hyponatremia, which was corrected, but sensorium did not show improvement and was noted to have reduced limb movements. Computed tomogram (CT) brain was taken which showed no acute infarct or hemorrhage; however, there was hyperdensity involving left eye with Hounsfield unit (HU) of 93. [Figure 1] There was no external evidence of trauma to eye. The possibility of intraocular bleed was initially suspected; however, in view of negative history of trauma to head or eye with negative eye findings, other possibilities were considered. On probing further into history, his son revealed a history of surgery done for visual impairment; hence, the possibility of an intraocular radio-opaque injection was considered. On further checking his records, there was documentation of vitrectomy following retinal detachment. Intraocular silicone oil injection was done 2 years back. He had vision loss in the left eye with finger counting only.
|Figure 1: Nonenhanced computed tomogram axial image of brain at the level of pons and medulla showing uniform intra ocular hyperdensity of left eye|
Click here to view
| Discussion|| |
Intraocular silicone oil has been used as a long-term endotamponade agent in the management of complicated retinal detachment as well for vitreous replacement. Silicone oil is transparent, but radiodense, with a CT attenuation of 106–138 HU that is slightly higher than in hemorrhage (50–90 HU). Radiological clue is hyperdensity in orbit is well defined taking the shape of the intraocular cavity and is generally of homogenous density. It is hyperintense relative to water in magnetic resonance imaging (MRI) T1-weighted sequences, whereas in T2 images it is usually hypointense relative to water. The hyperdense appearance of intraoular silicone oil could be misinterpreted as acute, intraocular hemorrhage by the unwary clinician, unless the appropriate history is obtained.
In our patient also, there was a history of trauma, but there was no external evidence for ocular trauma. CT HU value of intraocular hyperdensity was 93 in our patient, so quite confusing for a vitreous hemorrhage.
However, silicone oil can migrate into the anterior chamber of the eye and can accumulate in the peri-orbit after escaping the eye through sclerotomies. It is well known that this foreign material may lead to serious intraocular complications such as intraconjunctival oil inclusion cysts, band keratopathy, secondary glaucoma, cataract formation, and subretinal migration of oil, severe optic neuropathy as well as intracranial migration of silicone oil.,,
| Conclusion|| |
Intraocular silicone oil has unique imaging characteristics with which the treating physician as well as radiologists must become familiar otherwise it can be mistaken for an intraocular hemorrhage. Detailed history taking including history of retinal surgery should be included when such an intraocular hyperdensity is noted on imaging.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Saw SM, Gazzard G, Wagle AM, Lim J, Au Eong KG An evidence-based analysis of surgical interventions for uncomplicated rhegmatogenous retinal detachment. Acta Ophthalmol Scand 2006;84:606-12.
Nazemi PP, Chong LP, Varma R, Burnstine MA Migration of intraocular silicone oil into the subconjunctival space and orbit through an ahmed glaucoma valve. Am J Ophthalmol 2001;132:929-31.
Grzybowski A, Pieczynski J, Ascaso FJ Neuronal complications of intravitreal silicone oil: An updated review. Acta Ophthalmol 2014;92:201-4.
Filippidis AS, Conroy TJ, Maragkos GA, Holsapple JW, Davies KG Intraocular silicone oil migration into the ventricles resembling intraventricular hemorrhage: Case report and review of the literature. World Neurosurg 2017;102:695.e7-10.
Mathis S, Boissonnot M, Tasu JP, Simonet C, Ciron J, Neau JP Intraventricular silicone oil: A case report. Medicine 2016;95.