SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS OF RETAINED SUBRETINAL PERFLUORO-n-OCTANE

Abstract

Subretinal PFO appears as a low-reflectance spherical mass, often with a pinpoint focus of hyperreflectance at the apex of the bubble. Optical coherence tomography details beneath subretinal PFO appear relatively hyperreflectant compared to adjacent tissue. Long-term observation revealed preferential absence of the outer retinal layers with no nerve fiber layer erosion, subretinal inflammatory precipitates, or proliferative vitreoretinopathy. Some evidence of retinal pigment epithelial disruption was observed but seemed to remain stable or improve with observation. The authors suggest management involving follow-up with close observation in SR-PFO unless present in the subfoveal region. Choroidal neovascular membrane can occur after SR-PFO removal and may be successfully managed with intravitreal bevacizumab.

Optic coherence tomography features of subretinal vitreous substitutes

“…The pinpoint focus of hyper-reflectance at the apex of the PFO bubble has also been previously described and helps to distinguish PFO from cysts [9]. We have found this sign in most of the retained PFO cases, as well as in cases of gas or SO, and therefore it does not seem to help differentiate among different subretinal VS. A hyperreflective halo around the bubble at the subretinal space, as described in Figs.…”

“…Some SD-OCT features of subretinal PFO have already been described and help distinguish it from cysts or subretinal fluid [9,10,14], but no attempt in literature so far tried to differentiate subretinal PFO from gas or SO. Previous attempts to describe OCT features of subretinal SO dealt with emulsified particles, described on OCT as subretinal hyper-reflective spherical bodies, usually at the border of a macular hole [6,7], but there is no previous literature so far describing SD-OCT features of retained subretinal non-emulsified SO.…”

“…SD-OCT aspects of retained subretinal PFO have been described and help distinguish PFO from residual subretinal fluid, macular cysts or cystoid macular edema [9,10],…”

Retinal pigment epithelial step sign: optical coherence tomography clue for diagnosing retained subretinal perfluorocarbon liquid

“…Optical coherence tomographic (OCT) features of a retained subretinal perfluorocarbon liquid (PFCL) include an omega-shaped conformation of the cyst, acute angle between the retinal pigment epithelium (RPE) and the neurosensory retina, compressed overlying retinal layers and an RPE hyper-reflective band with hyper-reflective shadowing of the underlying choroid. 1 Since submacular PFCL mandates urgent removal, hence its recognition and differentiation from mimickers are crucial. We present an OCT clue indicating presence of retained subretinal PFCL and discuss its utility herein.…”

“…The incident signal from the OCT (and reflected signal from sub-PFCL RPE) would experience refraction at the surface of PFCL bubble (Snell's law) giving us the illusion that sub-PFCL RPE is raised. 1 It is noteworthy that refraction occurs only when the light is incident obliquely to the medium and not along a normal drawn to it. Strampe et al 2 have reported image artefacts of handheld spectral domain OCT images of retained PFCL droplets on the surface of the retina ascribing to a lensing effect produced by the refractive index differences between the PFCL and vitreous humour.…”