Optic coherence tomography features of subretinal vitreous substitutes

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 C(3)F(8) 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.