Intra-retinal silicone oil following silicone oil removal

January 1, 2023
David I.T. Sia MBChB FRANZCO¹, Mark E. Seamone MSc MD FRCSC², Chad Baker MD FRSCS¹
¹Department of Ophthalmology and Visual Sciences, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.


A 58-year-old man presented with a rhegmatogenous retinal detachment (RRD) 1 month following full thickness macula hole repair. He underwent emergent surgery with silicone oil tamponade. Five months later the silicone oil was removed. During the removal, emulsified silicone oil was noted. At his 2-week post-operative review, multiple spherical globules were noted on the en-face infrared image within the area of the macula that had internal limiting membrane (ILM) peeled (Fig. 1a). Spectral domain optical coherence tomography (SD-OCT) demonstrated intra-retinal hypo-reflective foci (arrowhead) which are presumed to be emulsified silicone oil droplets within the retina (Fig. 1b).


Emulsification is when a liquid splits into small bubbles and are unable to coalesce with the larger bubble. Several factors can promote silicone oil emulsification after a retinal detachment repair, including protein surfactants, contaminants, low molecular weight and viscosity and shear forces.{Miller, 2014 #4} The biggest factor for emulsification remains the duration of the silicone oil tamponade. Toklu et al. examined thirty-two patients in whom silicone oil was preferred to remain in the eye as long as possible following retinal detachment surgery, and found that first signs of emulsification were noted between 5 and 24 months with a mean of 13.2 month.{Toklu, 2012 #3} The complications of emulsified silicone oil most commonly occur in the anterior segment in the form of keratopathy and glaucoma.{Miller, 2014 #4} The literature is less defined regarding the complications of emulsified silicone oil in the retina. With advancement of imaging techniques, silicone oil has been successfully identified within the retina, optic nerve and even the ventricles.{Miller, 2014 #4} It is hypothesized that the defects in the ILM following a membrane peel provides an entryway for the emulsified silicone oil to enter the intraretinal space and this can potentially cause secondary impairment of retinal function due to chronic inflammation.{Chung, 2003 #1}{Mrejen, 2014 #2}