Optic coherence tomography features of subretinal vitreous substitutes

Abstract

Background To draw comparisons between spectral domain optic coherence tomography (SD-OCT) features of subretinal silicon oil (SO), perfluoro-n-octane (PFO) or C3F8 gas. Methods Cases diagnosed with retained subretinal vitreous substitutes (VS) were retrospectively selected. Demographic data were collected and OCT features were analyzed. Results In the 13 cases with subretinal PFO, hyper-reflectivity under the bubble was noted in 8 eyes (61.5%); choroidal shadow at the borders of the bubble in 11 eyes (84.6%); hyper-reflective halo around the bubble in 5 eyes (38.4%) and a hyper-reflective apical dot in 8 eyes (61.5%).The two cases with multiple PFO bubbles had complete septum dividing the bubbles. The one case with subretinal SO had hyper reflectivity under the bubble; no choroidal shadow at the edge of the bubble; hyper-reflective halo was noted around the bubble and the apical hyper-reflective dot was present; there was no complete septum dividing multiple bubbles. The single case with subretinal C3F8 had some bubbles with totally round base, incomplete septum, hyper reflectivity under the bubble, choroidal shadow at the edge of the bubble, a hyper-reflective halo and an apical dot. Conclusion Different subretinal VS share similar SD-OCT characteristics. Round base bubbles are only observed with subretinal C3F8 gas, while incomplete septum are related to retained subretinal SO or gas.

InTraocular EMulsion of Silicone oil (ITEMS) grading system: an evidence-based expert-led consensus.

“…10 Microcystic macular changes caused by persistent SiO emulsion bubbles should not be confused with small hyporeflective spherical bodies in the subretinal space, which more likely are residual SiO globules with an incomplete septum among them, a feature that has been named the “caterpillar sign”, and casting a choroidal shadow at the borders of the bubbles. 29 In addition, SiO has been associated with macular thinning, mainly related to the reduced thickness of inner retinal layers. 5…”

“…10 Microcystic macular changes caused by persistent SiO emulsion bubbles should not be confused with small hyporeflective spherical bodies in the subretinal space, which more likely are residual SiO globules with an incomplete septum among them, a feature that has been named the "caterpillar sign", and casting a choroidal shadow at the borders of the bubbles. 29 In addition, SiO has been associated with macular thinning, mainly related to the reduced thickness of inner retinal layers. 5 The inclusion of disk OCT in the grading system was recommended as the detection and quantification of SiO emulsion at the optic nerve head may help in elucidating the role of emulsified SO in the pathogenesis of SiO-related optic neuropathy.…”

Subretinal silicone oil: OCT imaging findings and surgical management of a rare and unusual iatrogenic complication of retinal detachment surgery

“…Various liquids and tamponade agents are used during retinal detachment surgery, and surgeons must take great care to avoid them being retained in the vitreous cavity or migrating subretinally. There are a number of reports in the literature demonstrating retained heavy liquid (PFCL) under the retina and techniques described to remove it 1–6. However, there is a paucity in the literature of similar problems with silicone oil.…”

“…Retained silicone oil has a similar OCT appearance to retained heavy liquid, and had both of these substances been used during the surgery, in our case, it may have been difficult to determine preoperatively what the offending liquid was. An article by Zacharias et al nicely demonstrated the key features of retained heavy liquid including elevation of the RPE/heavy liquid interface, a hyper-reflective halo around the bubble, a hyper-reflective dot on the apex of the bubble and a complete septum if multiple bubbles are present 2. Unfortunately, they only had one case with silicone oil subretinally, but this case had a hyper-reflective halo and a choroidal shadow at the edge of the bubble on OCT scan similar to the PFCL cases but in contrast lacked the complete septum seen in subretinal PFCL 2.…”

“…An article by Zacharias et al nicely demonstrated the key features of retained heavy liquid including elevation of the RPE/heavy liquid interface, a hyper-reflective halo around the bubble, a hyper-reflective dot on the apex of the bubble and a complete septum if multiple bubbles are present 2. Unfortunately, they only had one case with silicone oil subretinally, but this case had a hyper-reflective halo and a choroidal shadow at the edge of the bubble on OCT scan similar to the PFCL cases but in contrast lacked the complete septum seen in subretinal PFCL 2. The OCT image (figure 2) of our patient did not demonstrate the elevation of the RPE/oil interface or apical hyper-reflective dot seen with PFCL.…”