Contiguous Silicone Oil Migration From the Vitreous Cavity to the Optic Tract

Letters to the Editor future preflight, in flight and postflight analysis of the optic discs and choroid by optical coherence tomography as well as ultrasound and MRI examination of the globe and optic nerve sheaths, may provide important information for analysis. Thomas H. Mader, MD, COL(R) US Army, Cooper Landing, Alaska C. Robert Gibson, OD Coastal Eye Associates, Webster, Texas Christian A. Otto, MD Weill-Cornell Medical College, New York, New York Ashot E. Sargsyan, MD KBRWyle, Houston, Texas Neil R. Miller, MD Wilmer Eye Institute, Baltimore, Maryland Contiguous Silicone Oil Migration From the Vitreous Cavity to the Optic Tract W e would like to applaud Boren et al (1) for their article "Retrolaminar migration of silicone oil." We evaluated a patient who adds to the spectrum of neuroimaging findings of this disorder. A 92-year-old man with a longstanding history of glaucoma underwent vitrectomy with silicone oil endotamponade in his right eye for a retinal detachment 3 years previously. Because of transient right hand weakness and gait ataxia, brain MRI was performed. This showed hyperdense material involving the right optic nerve, optic chiasm, and right optic tract (Fig. 1). Automated visual fields showed changes consistent with advanced glaucoma, but a homonymous defect was not detected. We are unaware of previous reports of optic tract involvement with silicone oil. Perimetry showed that it did not cause homonymous visual field loss, supportive of the 2 asymptomatic cases reported by Boren et al. Given that the mechanism of intracranial silicone oil migration is not yet fully understood, future postmortem histopathological examination of the eyes and 464 Prem S. Subramanian, MD, PhD Department of Ophthalmology, University of Colorado, Aurora, Colorado Stephen F. Hart, MD Life Sciences Division, NASA, Houston, Texas William Lipsky, MD Coastal Eye Associates, Webster, Texas Nimesh B. Patel, OD, PhD Department of Vision Science, University of Houston, Houston, Texas Andrew G. Lee, MD Department of Ophthalmology, Methodist Hospital, Houston, Texas The authors report no conflicts of interest. brain will be essential in better understanding this disorder. Samantha Bobba, MD Prince of Wales Hospital, Sydney, Australia Olivia J.K. Fox, MBBS Mitchell B. Lee, MBBS Nepean Hospital, Sydney, Australia Richard Parker, MBBS Department of Ophthalmology, Save Sight Institute, Sydney Eye Hospital, Sydney, Australia Neera S. Jain, MD Prince of Wales Hospital, Sydney Alison K. Semmonds, BMed FRACP St Vincent's Private Hospital, Lismore, Australia Letters to the Editor: J Neuro-Ophthalmol 2017; 37: 458-465 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Letters to the Editor FIG. 1. Brain MRI. A and B. Axial fluid-attenuated inversion recovery (FLAIR) images show hyperintense material in the right eye (arrow) and right optic nerve (white arrowhead) as well as the right side of the optic chiasm (dashed arrow) and right optic tract (open arrowhead). C. Coronal T2 scan reveals hyperintense material in the right optic tract (arrow). D. Axial T2 image with fat suppression shows the material to be hypointense within the eye (arrow) and right optic nerve (dashed arrow). A small amount of fluid vitreous is present posteriorly (white arrowhead) within the right eye. Ashish Agar, PhD FRANZCO Ian C. Francis, PhD FRANZCO Department of Ophthalmology, Prince of Wales Hospital, Sydney, Australia Letters to the Editor: J Neuro-Ophthalmol 2017; 37: 458-465 The authors report no conflicts of interest. REFERENCE 1. Boren RA, Cloy CD, Gupta AS, Dewan VN, Hogan RN. Retrolaminar migration of intraocular silicone oil. J Neuroophthalmol. 2016;36:439-447. 465 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.